Ambient is a part of the MorphOS and gets regular updates. You can grab the sources from https://www.morphos-team.net/sources

Open it and remove the dust. Battery is a CR2032 cell, probably worth replacing. If HDD is stock it can be quite slow and loud even for a HDD, unfortunately Mac Mini G4 uses IDE interface, so fitting a SATA, M.2 drive can be a bit problematic with adapters.

From MorphOS point of view - MacOS X can be useful to silence the startup beep, as it can't be done from MorphOS or Openfirmware. It should be possible also from Linux. As long as PRAM battery works you can do it once and forget about it.

You could make an image of your existing MacOS X installation and bring it back if needed.