Okay, new version, this time with info when something fails and a fix of a rather serious bug that caused checkmark settings to be ignored.
Alex, think you could test again? Installing on top of the old install shouldn't matter, but could you delete your .local/reaper dir, just to be sure?
https://stash.reaper.fm/oldsb/243523/LinReaper0.4.run
--edit--
About having to make the file executable, then I don't think there's any way to avoid doing that - if anyone has any ideas to how we can avoid it, please do write.