The difference between LO8 and PLO8 that I have seen so far is captured in 1 word: "and"

In limit, it's fine to have half the hand locked or drawing to it, and even if it gets counterfeited, you're okay. In PL, you want a piece of the flop *and* something else to fall back on if you're going to get a lot of money in there. Redraws to a low, a flush, counterfiet protection, etc. are much more crucial.