Recently, my group discovered VSee, a communication software much like Skype or Hangouts, but with a huge advantage when used in conjunction with OBS: in VSee, each camera opens a new window.
Those windows can be resized at you pleasure, can be pinned on specific parts of your desktop, and you can save where they are, so when you open VSee again, the windows will be right there on that exact spot.
When configuring OBS, you can assign that windows to a place on your layout, so each time you open OBS, VSee and Fantasy Grounds, everything will be in place as the last time you used them. Better, since each person have it’s own window, if someone enter or leave the conference, it won’t mess up your layout.
The only issue I noticed in VSee is that, when more than six people get in the conference, the cameras start to lag a lot, but this could be my own connection, because I am recording the games and also usually DMing them.
VSee can be found here (it is free):
https://vsee.com/
And here are some examples of my recorded games using this setup (sorry, they are in portuguese... lol)
https://www.youtube.com/watch?v=6L2DzNc4VVg&t
https://www.youtube.com/watch?v=Q4akyB39sN8
(this one don't have cameras on, but shows how I had improved the previous layout)
https://www.youtube.com/watch?v=w4TNCrA2Trs&t