Hey Philipp! The exact same issue has been reported to us in regards to Envelope Follower. Considering that Envelope Follower also seems to be able to cause Live to freeze at random moments as you described in this other thread, it is clear that both devices are bugged. They leverage the same mechanism to map to parameters, and our current suspicion is that the problem is that exact mechanism (the [live.remote~] and [live.modulate~] objects).
Related reports also indicate that the problems keep occuring without our Videosync or Beam running alongside Live, so it is a problem on Live’s side and therefor something only Ableton can fix. What they will need to do so is a reliable way to reproduce the bug. If you have a way to do so or can demonstrate it with a screen recording, please report this to Ableton directly.
When it comes to a direct way to modulate Videosync’s parameters: there currently isn’t any other than automation or clip modulation. This is something we are looking to improve.