Ender-3 V3 SE: config settings to roll our own firmware please

Ender Series Creality Ender-3 V3 KE/SE
94

While I have wise heads with experience:

  • Ender3v3SE
  • Just added Creality runout sensor
  • It does not communicate with Octoprint - even with modified Marlin.

Will I need to go back to an SD card (like an animal) to get my huge ($AU30) investment to work, or do I have to drop Marlin (after this good fight!) & go to Klipper?

Will it work if I use Klipper on a spare miniPC (as I has no money or RPi’s available), as it does with Creality’s Sonic Pad?

Thanks in advance!