As you said Google won't help with this issue - however if you report it to them you can push to get it added to the internal case between Google and Larian. Obviously the more instances both the higher the priority and the more examples Larian get to find correlation.

I think it has something to do with Google storage hitting limits and there not being enough space on the profile to create game files leading to a timeout and a crash.... But that's just a guess based on a sample size of one. Others have said they only had a couple of saves on their account (after cleaning it down) and experiencing the same.

They're definitely working on it from my ticket with Larian, but they haven't yet been able to reproduce it, so a fix may be a while off still.