I was advised by Sketch’ team to turn off Versions only for Sketch with a command:
defaults write com.bohemiancoding.sketch3 ApplePersistence -bool no
2 years ago I ran into similar problems, to the point that I nearly lost a client for being “unprofessional” in using Sketch instead of Photoshop.
In my case, the Sketch Versions files ended up filling my entire disk without me noticing due only to the vast size of the file (hundred boards).
This meant that one day, OSX just stopped booting up, I had no repair partition due to messing up my Boot Camp installation, and needed 3 days to recover, with no backup laptop, I now carry a spare Air because of that episode — haven’t needed it.