Thank you!
To make more clear what we need/want. We use Temporal, but we use Advanced Visibility features very rarely. We are fine with read operations taking long, as long as the write operations are fast.
We figured out the operational cost of managing ES is too high for us, taking into consideration we already do manage Postgres and have operations (backups, compliance, etc) around it set-up well. (We had a ES crash as I wrote here).
That being said, we are a bit scared to use something labeled as “beta” in production, if it’s in some way unstable and can cause the whole Temporal to behave undeterministic. (I don’t mean in Temporal terms 
just to behave weird.)
So the question for us is - is switching from visibility ES to Postgres generally safe, given that we use it very little, and we just want the rest of the app work fine.