I find in most dungeons where it's available that I use E. Moulinet at least once per trash phase before the bosses, and still be able to get my mana back up in time to open with the single-target melee combo on the boss (or at least enough to reach that point via Manafication). I see no problem with using it to burn through bigger trash mobs faster, since it's three instant hits compared to getting maybe two casts of Scatter in at the same amount of time. In any case, adding an AOE finisher at the end of a triple-E. Moulinet wouldn't be bad either. In fact, it wouldn't surprise me at all if it's already been in the plans for future expansions. Beyond that and potentially adding another neutral OGCD AOE, I see no reason to bog the kit down with any further AOEs.