They started right when the KR servers went live. Lots of fun watching them rage and then be really happy when they finish a mission. The timer says 16.5 hours and counting. They have been switching off, but JYP seems like he has been playing the most (especially the more difficult missions). They aren't particularly rushing (watching scenes, taking short breaks, etc). The timer has not be paused.
They have multiple cameras around the house, and the scene will change periodically.
Also, Gyuri is on stream sometimes. She was last seen in the kitchen making food / washing dishes (not joking) lol. You can hear her laugh in the background. Sometimes they will switch the camera to the kitchen.
MMA recently showed up.
There are actually a decent number of streamers and viewers for LotV on Afreeca.
Edit: "Mission Clear!" photos (not a spoiler)