So this issue is in build 801 and likely to affect other builds. Occasionally while hanging out I've noticed that sometimes everyone in the room will suddenly freeze and go quiet for a couple of seconds as if I lost internet connection, then everything suddenly attempts to catch up. I thought it was just me at first, but my friends and I figured out it actually affects everyone in the room at the same time, sometimes even resulting in broken mics. It's entirely possible this is due to the networked IK system, but could also be something else entirely, so it's worth looking into. And once it starts happening it keeps happening until you switch worlds.