It changes over time.
I find box squats in conjuction with plyos to always help my squat. Granted, there are million different box squat variations.
If I had to choose one box squat variation... then I'll go with manta ray wide stance to just below parallel. The manta ray implement makes the squat something that I can do sustainably since it takes pressure off my hips, shoulders, and elbows.
Box squats in general are helpful because they help me pop out of the whole and make my sticking point somewhere I have a fighting chance of straining to get the weight up.
The box squat also takes a ton of stress off the joints since the energy you store on the descent is dissipated through the box instead going through the body to assist in the rebound. You also just can't use as much weight.
Building meat around the shoulders with bodybuilding and re/pre-hab movements keeps me healthy enough to bench consistently. The other thing is DE type benching.
For deadlift, any DL variation that I don't use a belt. It forces me to use good form and hence build my weaknesses.