Maximum/optimal number of checkers/transfers for Google Drive?

I’m currently trying to determine the maximum number of checkers/transfers for uploading to Google Drive–that is, the maximum number before I get a “rate limit exceeded” error. Doing so will likey reduce the load on the rclone “pacer” (and my cpu), thus speeding things up (hopefully). I think it’s pretty well known that Google Drive API is pretty restrictive on their query rates, so I’d assume that even with my own client id & secret I wouldn’t be exactly be able to run 50 checkers or whatever. Does anyone know the limit? I mean, I don’t want to run 20 or 30 checkers when only a few would max out Drive’s API.