[hot_gril]

The only potential issue I've seen with cloud managed DBMSes is latency between application and DB, since they might be far apart. But that's something you check out day 1 and move away from if it's not tolerable. I would totally start there, not try to set it up myself.

[riku_iki]

another obvious move would be moving app to the same cloud too..

[hot_gril]

Well there's same region, same AZ (if AWS), and same machine. Different levels of location for GCP or whatever. Same machine is probably never doable on a cloud provider, but it's rare that you'll need that.