RXPS: use measured preamble-symbol capture model

platformio.ini

@@ -29,6 +29,15 @@ build_flags = -w -DNDEBUG -DRADIOLIB_STATIC_ONLY=1 -DRADIOLIB_GODMODE=1
   -D LORA_FREQ=869.618
   -D LORA_BW=62.5
   -D LORA_SF=8
+  ; TCXO startup delay in microseconds, written by CustomSX1262/CustomLR1110
+  ; after begin(). RadioLib defaults to 5000 and nothing used to override it, so
+  ; every board paid 5 ms on every duty-cycle wake. Lowest working value measured
+  ; on five modules: T096 400, Tracker V2 300, Waveshare 150, ThinkNode M3 200,
+  ; T1000-E 200 us - 1600 keeps 4x margin over the worst of them. It also feeds
+  ; the RXPS sleep floor and timer guard (transition = this + 1000), so lowering
+  ; it makes low-SF profiles armable that were not. A board needing its own value
+  ; puts -D MC_TCXO_DELAY_US=... in its own build_flags; the later -D wins.
+  -D MC_TCXO_DELAY_US=1600
   -D ENABLE_ADVERT_ON_BOOT=1
   -D ENABLE_PRIVATE_KEY_IMPORT=1   ; NOTE: comment these out for more secure firmware
   -D ENABLE_PRIVATE_KEY_EXPORT=1