That maschine.rs tool looks intriguing, though limited to mk2 (I have mkiii). It keep seems to connect it as a midi device, for use in midi mode, which is not my main use case. I may try though. If I just want a midi pad controller there are plenty of choices beyond maschine, whose actually killer feature is full edit workflow through its own interface (connected to PC, yes, but you can avoid using the computer for the most part).

Someone mentioned darktable. I am familiar with it - it's a perfectly serviceable interface/non-destructive editor, but it's the interoperability/workflow that lightroom provides that is the secret sauce (ie - all devices, edit anywhere, sync to desktop (where I keep originals and do heavier edits) and back). I'll look at darktable again now that I have an install.

At some point (with some use cases) the Linux desktop switch becomes an exercise of putting a square peg in a round hole - an uphill battle of shoehorning in workarounds. I'm game to try - pls don't read this as being dismissive - but I've gone down this path many, many, many times.

The real answer (pie in the sky) is to get commercial product manufacturers to actually support Linux. Snaps exist (software can be done even if inefficiently), but HW requires commitment from the builders.