At my company we were using Teams' "common" conferences with 230 (1st week) and 250 (2nd week) participants without issues. In this case 248 were listening and 1-2 were talking/videocasting.
Due to there being a 250 participant limit we now switched to live events, and there also has been no issue with that.
Due to there being a 250 participant limit we now switched to live events, and there also has been no issue with that.