I think the bard's LB is perfectly spot on, keep in mind that if a party needs a healing limit it means that either the healers are dead or they are in deep shit and can't stop healing for a sec and the LB casting time is quite long, so having a support job doing it is the way to go. Honestly most of the time I've seen that LB it was done by a bard and I myself have saved a few pugs from a wipe with it.
And don't forget that using a limit is optional, you can complete every fight without using any LB.