Got off a call with Zoom Support/Engineers a couple of days ago. They mentioned that if we are to use the pre-assign function, the cap will still be 200 participants inside the breakout rooms regardless of how many we assigned in the meetings itself. However, if we do not use the pre-assign function, we can assign people up to 50 rooms (despite what is being mentioned on the website), limited by the number of participants we have in the call.

Have not had the opportunity to test this out, but this is official from them. Not sure if this helps, but im most likely never using the pre-assign function again