I can at least confirm a freshly reseted and upgraded Jolla 1 has no issues.
Quite telling that i can not remember if it was 8 or 10 upgrades...
When going from 1.2 to 2.0 all the Jolla apps tried to reinstall themselfes and failed after >10minutes of trying each. I force rebooted with no errors afterwards but i suggest to not install any (Jolla) apps at the start like i did.

Wasn't there some full image for the Jolla 1 to flash and skipping many updates?

Here https://talk.maemo.org/showthread.php?t=100528