Updates Zwitft in Omnirom don't work

I use a raspberry pi with Omnirom with Zwift.
Updating fails always; I have to remove zwift and then reinstall it (and do all the needed settings again).
Unfortunately these updates seem to be always mandatory, and come about every 2 weeks.

So 2 questions: how can I make updates working, without deinstalling/reinstalling again and again?
And why are these updates always mandatory? I can understand that if it’s about a serious security problem, but is that always the case?

That is not a support OS.