I made my Lae'zel a Battle Master warrior, and so far when I use menacing attacks (ranged or melee) it seems that a Superiority die is not being used, or if it is used it seems that the counter area in the hud is not being iterated. I think it's not being used, however, because I seem to be able to continue to use the moves past the 4 you initially get even without resting.