Can’t say I’ve taken the time to test the limits for sure
But I do often when I need chat samples, will get the first 100 live streams, concat the logins and fire that off to a join.
but I tend to only do 2 or 3 pages. (so 200 or 300 channels at most anyway).
Since “attempts” means if you try to join a banned channel, thats still “an attempt”. Generally I don’t get near rate limits so I’ve not tested the true practical limits of what works/doesn’t work. However when I’m also operating as a verified bot.