Yyou can take some weight off the belt by going to a steel backplate and weighted STA. In doing this with an AL3 and my 3mm suit I need no weight. With my dry suit and all my undergarments ~40f water it really pays off as I can put the needed weight into the pockets and not need a belt. Keeps things streamlined.
While YMMV it surely pays to try different configurations to find one that is comfortable and works for you.
Best fishes!! [