LB20 works on a
mauler, too. This isn't optimized, but it works as an ambusher.
Also, I wish we could all get away from these threads where someone says a weapon doesn't work, but doesn't give any consideration to the rationale for choosing the weapon in the first place. Does the LB family work in general for PPFLD or opening round trading? No. It wasn't ever supposed to.
Sure, the maps, the play styles, and the mechanics of MWO make certain weapons more useful in general, but sometimes it's a lot of fun to make a specialist build using a specialist weapon like the LB20.