diff --git a/code/espurna/button.cpp b/code/espurna/button.cpp
index bfa2c39a..8021ca58 100644
--- a/code/espurna/button.cpp
+++ b/code/espurna/button.cpp
@@ -832,13 +832,14 @@ void buttonSetup() {
     terminalRegisterCommand(F("BUTTON"), [](const terminal::CommandContext& ctx) {
         unsigned index { 0u };
         for (auto& button : _buttons) {
-            ctx.output.printf("%u - ", index++);
+            ctx.output.printf_P(PSTR("%u - "), index++);
             if (button.event_emitter) {
                 auto& pin = button.event_emitter->pin();
-                ctx.output.println(pin->description());
+                ctx.output.print(pin->description());
             } else {
-                ctx.output.println(F("Virtual"));
+                ctx.output.print(F("Virtual"));
             }
+            ctx.output.print('\n');
         }
 
         terminalOK(ctx);
diff --git a/code/espurna/ifan.cpp b/code/espurna/ifan.cpp
index f1563af8..ed8a0ba0 100644
--- a/code/espurna/ifan.cpp
+++ b/code/espurna/ifan.cpp
@@ -351,7 +351,9 @@ void setup() {
             updateSpeedFromPayload(ctx.argv[1]);
         }
 
-        ctx.output.println(speedToPayload(config.speed));
+        ctx.output.printf_P(PSTR("%s %s\n"),
+            (config.speed != FanSpeed::Off) ? "speed" : "fan is",
+            speedToPayload(config.speed));
         terminalOK(ctx);
     });
 #endif
diff --git a/code/espurna/light.cpp b/code/espurna/light.cpp
index c3ff380c..7167a94e 100644
--- a/code/espurna/light.cpp
+++ b/code/espurna/light.cpp
@@ -1834,7 +1834,7 @@ void _lightInitCommands() {
             _lightFromRgbPayload(ctx.argv[1].c_str());
             lightUpdate();
         }
-        ctx.output.println(lightRgbPayload());
+        ctx.output.printf_P(PSTR("rgb %s\n"), lightRgbPayload().c_str());
         terminalOK(ctx);
     });
 
@@ -1843,7 +1843,7 @@ void _lightInitCommands() {
             _lightFromHsvPayload(ctx.argv[1].c_str());
             lightUpdate();
         }
-        ctx.output.println(lightHsvPayload());
+        ctx.output.printf_P(PSTR("hsv %s\n"), lightHsvPayload().c_str());
         terminalOK(ctx);
     });
 
@@ -1852,7 +1852,7 @@ void _lightInitCommands() {
             _lightAdjustKelvin(ctx.argv[1].c_str());
             lightUpdate();
         }
-        ctx.output.printf("%ld\n", _toKelvin(_light_mireds));
+        ctx.output.printf_P(PSTR("kelvin %ld\n"), _toKelvin(_light_mireds));
         terminalOK(ctx);
     });
 
@@ -1861,7 +1861,7 @@ void _lightInitCommands() {
             _lightAdjustMireds(ctx.argv[1]);
             lightUpdate();
         }
-        ctx.output.printf("%ld\n", _light_mireds);
+        ctx.output.printf_P(PSTR("mireds %ld\n"), _light_mireds);
         terminalOK(ctx);
     });
 
diff --git a/code/espurna/rpnrules.cpp b/code/espurna/rpnrules.cpp
index 2a70cc41..707d47f9 100644
--- a/code/espurna/rpnrules.cpp
+++ b/code/espurna/rpnrules.cpp
@@ -553,14 +553,12 @@ void _rpnRfbSetup() {
         for (auto& code : _rfb_codes) {
             char buffer[128] = {0};
             snprintf_P(buffer, sizeof(buffer),
-                PSTR("proto=%u raw=\"%s\" count=%u last=%u"),
-                code.protocol,
-                code.raw.c_str(),
-                code.count,
-                code.last
-            );
-            ctx.output.println(buffer);
+                PSTR("proto=%u raw=\"%s\" count=%u last=%u\n"),
+                code.protocol, code.raw.c_str(), code.count, code.last);
+            ctx.output.print(buffer);
         }
+
+        terminalOK(ctx);
     });
 #endif
 
@@ -589,20 +587,19 @@ void _rpnDeepSleep(uint64_t duration, RFMode mode) {
 }
 
 void _rpnShowStack(Print& print) {
-    print.println(F("Stack:"));
+    print.print(F("Stack:\n"));
 
     auto index = rpn_stack_size(_rpn_ctxt);
-    if (!index) {
-        print.println(F("      (empty)"));
+    if (index) {
+        rpn_stack_foreach(_rpn_ctxt, [&index, &print](rpn_stack_value::Type type, const rpn_value& value) {
+            print.printf_P(PSTR("%c      %02u: %s\n"),
+                _rpnStackTypeTag(type), index--,
+                _rpnValueToString(value).c_str());
+        });
         return;
     }
 
-    rpn_stack_foreach(_rpn_ctxt, [&index, &print](rpn_stack_value::Type type, const rpn_value& value) {
-        print.printf("%c      %02u: %s\n",
-            _rpnStackTypeTag(type), index--,
-            _rpnValueToString(value).c_str()
-        );
-    });
+    print.print(F("      (empty)\n"));
 }
 
 void _rpnInit() {
@@ -872,11 +869,10 @@ void _rpnInitCommands() {
 
         for (auto& runner : _rpn_runners) {
             char buffer[128] = {0};
-            snprintf_P(buffer, sizeof(buffer), PSTR("%p %s %u ms, last %u ms"),
+            snprintf_P(buffer, sizeof(buffer), PSTR("%p %s %u ms, last %u ms\n"),
                 &runner, (RpnRunner::Policy::Periodic == runner.policy) ? "every" : "one-shot",
-                runner.period, runner.last
-            );
-            ctx.output.println(buffer);
+                runner.period, runner.last);
+            ctx.output.print(buffer);
         }
 
         terminalOK(ctx);
@@ -885,8 +881,8 @@ void _rpnInitCommands() {
     terminalRegisterCommand(F("RPN.VARS"), [](const terminal::CommandContext& ctx) {
         rpn_variables_foreach(_rpn_ctxt, [&ctx](const String& name, const rpn_value& value) {
             char buffer[256] = {0};
-            snprintf_P(buffer, sizeof(buffer), PSTR("      %s: %s"), name.c_str(), _rpnValueToString(value).c_str());
-            ctx.output.println(buffer);
+            snprintf_P(buffer, sizeof(buffer), PSTR("      %s: %s\n"), name.c_str(), _rpnValueToString(value).c_str());
+            ctx.output.print(buffer);
         });
         terminalOK(ctx);
     });
@@ -894,8 +890,8 @@ void _rpnInitCommands() {
     terminalRegisterCommand(F("RPN.OPS"), [](const terminal::CommandContext& ctx) {
         rpn_operators_foreach(_rpn_ctxt, [&ctx](const String& name, size_t argc, rpn_operator::callback_type) {
             char buffer[128] = {0};
-            snprintf_P(buffer, sizeof(buffer), PSTR("      %s (%d)"), name.c_str(), argc);
-            ctx.output.println(buffer);
+            snprintf_P(buffer, sizeof(buffer), PSTR("      %s (%d)\n"), name.c_str(), argc);
+            ctx.output.print(buffer);
         });
         terminalOK(ctx);
     });
@@ -906,10 +902,10 @@ void _rpnInitCommands() {
             return;
         }
 
-        ctx.output.print(F("Running RPN expression: "));
-        ctx.output.println(ctx.argv[1].c_str());
+        const char* ptr = ctx.argv[1].c_str();
+        ctx.output.printf_P(PSTR("Expression: \"%s\"\n"), ctx.argv[1].c_str());
 
-        if (!rpn_process(_rpn_ctxt, ctx.argv[1].c_str())) {
+        if (!rpn_process(_rpn_ctxt, ptr)) {
             rpn_stack_clear(_rpn_ctxt);
             char buffer[64] = {0};
             snprintf_P(buffer, sizeof(buffer), PSTR("position=%u category=%d code=%d"),
diff --git a/code/espurna/settings.cpp b/code/espurna/settings.cpp
index fd42dcd0..8af979d3 100644
--- a/code/espurna/settings.cpp
+++ b/code/espurna/settings.cpp
@@ -458,15 +458,18 @@ void _settingsInitCommands() {
     terminalRegisterCommand(F("KEYS"), [](const terminal::CommandContext& ctx) {
         auto keys = settingsKeys();
 
-        ctx.output.println(F("Current settings:"));
+        ctx.output.printf_P(PSTR("Current settings:"));
+
+        String value;
         for (unsigned int i=0; i<keys.size(); i++) {
-            const auto value = getSetting(keys[i]);
-            ctx.output.printf("> %s => \"%s\"\n", (keys[i]).c_str(), value.c_str());
+            value = getSetting(keys[i]);
+            ctx.output.printf_P(PSTR("> %s => \"%s\"\n"), (keys[i]).c_str(), value.c_str());
         }
 
         auto available [[gnu::unused]] = settings::kv_store.available();
-        ctx.output.printf("Number of keys: %u\n", keys.size());
-        ctx.output.printf("Available: %u bytes (%u%%)\n", available, (100 * available) / settings::kv_store.size());
+        ctx.output.printf_P(PSTR("Number of keys: %u\n"), keys.size());
+        ctx.output.printf_P(PSTR("Available: %u bytes (%u%%)\n"),
+                available, (100 * available) / settings::kv_store.size());
 
         terminalOK(ctx);
     });
@@ -515,14 +518,14 @@ void _settingsInitCommands() {
             if (!result) {
                 const auto maybeDefault = settingsQueryDefaults(key);
                 if (maybeDefault.length()) {
-                    ctx.output.printf("> %s => %s (default)\n", key.c_str(), maybeDefault.c_str());
+                    ctx.output.printf_P(PSTR("> %s => %s (default)\n"), key.c_str(), maybeDefault.c_str());
                 } else {
-                    ctx.output.printf("> %s =>\n", key.c_str());
+                    ctx.output.printf_P(PSTR("> %s =>\n"), key.c_str());
                 }
                 continue;
             }
 
-            ctx.output.printf("> %s => \"%s\"\n", key.c_str(), result.c_str());
+            ctx.output.printf_P(PSTR("> %s => \"%s\"\n"), key.c_str(), result.c_str());
         }
 
         terminalOK(ctx);
diff --git a/code/espurna/terminal.cpp b/code/espurna/terminal.cpp
index 326d4712..459d3fcd 100644
--- a/code/espurna/terminal.cpp
+++ b/code/espurna/terminal.cpp
@@ -128,8 +128,10 @@ struct TerminalIO final : public Stream {
     // Buffer data until we encounter line break, then flush via Raw debug method
     // (which is supposed to 1-to-1 copy the data, without adding the timestamp)
 #if DEBUG_SUPPORT
-        if (!size) return 0;
-        if (buffer[size-1] == '\0') return 0;
+        if (!size || ((size > 0) && buffer[size - 1] == '\0')) {
+            return 0;
+        }
+
         if (_output.capacity() < (size + 2)) {
             _output.reserve(_output.size() + size + 2);
         }
@@ -137,6 +139,7 @@ struct TerminalIO final : public Stream {
             reinterpret_cast<const char*>(buffer),
             reinterpret_cast<const char*>(buffer) + size
         );
+
         if (_output.end() != std::find(_output.begin(), _output.end(), '\n')) {
             _output.push_back('\0');
             debugSendRaw(_output.data());
@@ -283,7 +286,7 @@ void _terminalInitCommands() {
             ? ctx.argv[1].toInt()
             : A0;
 
-        ctx.output.println(analogRead(pin));
+        ctx.output.printf_P(PSTR("value %d\n"), analogRead(pin));
         terminalOK(ctx);
     });
 
@@ -361,7 +364,7 @@ void _terminalInitCommands() {
     });
 
     terminalRegisterCommand(F("UPTIME"), [](const terminal::CommandContext& ctx) {
-        ctx.output.println(getUptime());
+        ctx.output.printf_P(PSTR("uptime %s\n"), getUptime().c_str());
         terminalOK(ctx);
     });
 
@@ -641,11 +644,11 @@ void terminalRegisterCommand(const __FlashStringHelper* name, terminal::Terminal
 };
 
 void terminalOK(Print& print) {
-    print.print(F("+OK\n"));
+    print.printf_P(PSTR("+%s\n"), "OK");
 }
 
 void terminalError(Print& print, const String& error) {
-    print.printf("-ERROR: %s\n", error.c_str());
+    print.printf_P(PSTR("-ERROR: %s\n"), error.c_str());
 }
 
 void terminalOK(const terminal::CommandContext& ctx) {
diff --git a/code/espurna/tuya.cpp b/code/espurna/tuya.cpp
index 4990153f..4f476e73 100644
--- a/code/espurna/tuya.cpp
+++ b/code/espurna/tuya.cpp
@@ -613,12 +613,13 @@ error:
 
             terminalRegisterCommand(F("TUYA.SHOW"), [](const terminal::CommandContext& ctx) {
                 ctx.output.printf_P(PSTR("Product: %s\n"), product.length() ? product.c_str() : "(unknown)");
-                ctx.output.println(F("\nConfig:"));
+
+                ctx.output.print(F("\nConfig:\n"));
                 for (auto& kv : config) {
                     ctx.output.printf_P(PSTR("\"%s\" => \"%s\"\n"), kv.key.c_str(), kv.value.c_str());
                 }
 
-                ctx.output.println(F("\nKnown DP(s):"));
+                ctx.output.print(F("\nKnown DP(s):\n"));
 #if LIGHT_PROVIDER == LIGHT_PROVIDER_CUSTOM
                 if (channelStateId) {
                     ctx.output.printf_P(PSTR("%u (bool) => lights state\n"), channelStateId.id());
diff --git a/code/espurna/wifi.cpp b/code/espurna/wifi.cpp
index ada6cf63..bde2c46d 100644
--- a/code/espurna/wifi.cpp
+++ b/code/espurna/wifi.cpp
@@ -1784,7 +1784,7 @@ void init() {
                     wifi::debug::mac(network.bssid).c_str(),
                     network.rssi, network.channel, network.ssid.c_str());
             } else {
-                ctx.output.println(F("STA: disconnected"));
+                ctx.output.print(F("STA: disconnected\n"));
             }
         }