I think that’s just a general testing framework for Jitsi, not a load generator.
50+ users on Jitsi is a challenge, though. You’d need a pretty beefy server to handle it, and even then it might be pushing some limits. I think the usual advice for giant meetings is to stream the meeting to YouTube and have view-only participants watch there.
You should also look at the “Last N” config options for that many users. Instead of everyone streaming their video up, it (theoretically) organizes people by who spoke last, and only the last N users send video up - other users effectively have their video stream auto-muted.