I’m in the same boat as you, with decades of projects I want to be able to open.
However, OP mentioned Reaper, which has a native Linux version! So as long as they’re not using a load of VSTs, and the ones they do play nicely with Linux, it could work out for them
The only way is to give it a go and find out though
Proton for ARM is not (currently) a thing, if that’s a factor