Based on a 3 year old thread (Is it possible to include the percentage complete of print done from the SD card of an Ender 3 with 4.2.2 with CR touch or BL touch - #8 by CRCinAU), it looks like M73 support should be enabled by default. I built a custom firmware using the firmware builder and when I send a command like M73 P25 R43 the printer response with Recv: echo:Unknown command: "M73 P25 R43"
Can an option be added to the builder to enable USE_M73_REMAINING_TIME?