OK. When I got my setup first, I played with the trim for a while. I found that with two on board and the pin in the third hole from the bottom, I got similar problems to yours. I dropped the pin a hole and the problems largely vanished. Yes, the transom angle will enter into that equation too. It's very much "suck it and see" territory.
I also found that it helped a lot to shift weight forward for the hole-shot, especially with 2 OB. A tiller extension was a huge help in this respect. A bit of white sink wastepipe and a bit of tape is good to experiment with to check if one would help you. I wouldn't leave shore without mine fitted. It is the 300/600mm telescopic type, the best of both worlds, IMO.