Clarify sanity-check for custom status bitmap (#20588)

Marlin/src/inc/SanityCheck.h

 #if ENABLED(SHOW_CUSTOM_BOOTSCREEN) && NONE(HAS_MARLINUI_U8GLIB, TOUCH_UI_FTDI_EVE)
   #error "SHOW_CUSTOM_BOOTSCREEN requires Graphical LCD or TOUCH_UI_FTDI_EVE."
 #elif ENABLED(CUSTOM_STATUS_SCREEN_IMAGE) && !HAS_MARLINUI_U8GLIB
-  #error "CUSTOM_STATUS_SCREEN_IMAGE requires a Graphical LCD."
+  #error "CUSTOM_STATUS_SCREEN_IMAGE requires a 128x64 DOGM B/W Graphical LCD."
 #endif
 
 /**

buildroot/tests/STM32F103VE_longer-tests

 
 use_example_configs Alfawise/U20
 opt_enable BAUD_RATE_GCODE
-exec_test $1 $2 "Full-featured U20 config" "$3"
+exec_test $1 $2 "CLASSIC_UI U20 config" "$3"
+
+use_example_configs Alfawise/U20
+opt_enable BAUD_RATE_GCODE
+opt_enable TFT_COLOR_UI
+opt_disable TFT_CLASSIC_UI
+exec_test $1 $2 "COLOR_UI U20 config" "$3"
+
+use_example_configs Alfawise/U20-bltouch
+opt_enable BAUD_RATE_GCODE
+exec_test $1 $2 "BLTouch U20 config"
 
 # cleanup
 restore_configs