At the grub config, append to the end of the "kernel" line:

      preempt=full

I would think that's the kind of thing the installer would take care of for you or that the app would modify on first launch. It's not reasonable to expect DAW end users to make those kinds of changes.

I don't know if any DAWs do any modifications for you, but I know Bitwig at least pops up a warning if realtime privileges aren't detected with a documentation link.