If anything, this demonstrates how much more important it is to raise preflop in pot limit games. When you have an edge on your opponents, why would you want to keep the pot small? Raise with your strong hands, both to get opponents to over-commit their equity and to fold off their equity, and fold your weak hands instead of paying bingo and hoping to hit a flop. Better to build a pot by betting strong preflop than to hope your opponent catches a strong enough piece of the board that they’ll bet/raise into your nuts postflop.