I had something with sg entities too it caused major hitching/fps drops until i spaced them about more ill find bug report might be related.
Wasn’t much of a report didn’t even get acknowledged(This was my first project i noticed the issue.
2nd Project
What i found tho is with sg entities the more you had in a small area it lags this i believe is around 1k iirc. I was testing a game with just a prefab with circle mesh_comp and it lags like crazy fps drops to 20 and it works on the world stream grid even if you have that disabled. I believe i can repro this every time (Just change the verse value for spawn amount) if you need any info as i still have the project