RE: 4 hand massage - I've tried and tried and frankly, four hands failed me each time, usually for different reasons.
Sometimes the boys are shy being with another boy and they don't let loose how they would if they were one on one.
One time I had one straight boy and one gay boy. Literally the straight guy is watching straight porn on his mobile to try and get hard. It became such a distraction, I had him leave. By then, my energy was off and I didn't even get happy ending.
It can be OK if the two are used to working together, one will work upper body while the other works lower body. Meeting in the middle.
I know some spots in BKK you can hire two boys who both bottom, one top one bottom, etc. I've heard one occasion where you can ask one masseur to fuck the other, but it seems to take away from the actual massage.
If I were you, I'd go for just one on one massage unless you want to try it out just for the sake of trying it.