I’ve had no major issues with that platform; I didn’t use any paid premium plan so initial requests would take slightly longer due to the way they run their servers. As for the database I was able to access it from a Roblox game and my tables are still there last time I checked, although I haven’t tested it with large amounts of data yet.
If OP is worried about volume databases aren’t anywhere as expensive as he claimed they were. A lot of them charge by the amount of usage and for a Roblox game it probably wouldn’t be much; maybe in the tens of dollars per month. I’ve never gone over my limit in the years I’ve had the server up.