custom setup against friends
You can do that with the Analysis Board setup in Live Chess. You can set up any position. You can make it invite only so that only your friend(s) could see it. You can have the board keep score and make sure moves are legal.
You would be the admin of the board. I think that only admins have control of the board. I am not sure if invited viewers can make moves or if you can enable that. If not, you can switch to make your friend the admin when it is their turn.
I'm not sure if anybody found a solution for this but as of now you can play with custom setup
Play > Play Computer > choose Position > Custom setup
Hope this helps, Cheers!