Yeah 99% of the time you only wanna use one of the two DPS limit breaks and they are pretty important for maximizing the party's DPS output. Occasionally in the end game if you mess up bad you'll use the tier 3 healer limit break that revives the entire party and puts them at full health. Tank LB is pretty much never used except in a couple of specific situations like early spiny kill in Garuda Ex. Basically Healer/Tank LBs are only used if you dun goofed.