I don't mind the occasional "LB" message in party chat. Sometimes I forget. Sometimes I don't notice how quickly we've been killing the boss. Sometimes I'm already casting it when the person reminds me. In any case, I don't mind it. I'd rather have someone remind me to use it than to forget about it entirely.

Also, I always appreciate it if there's a time when a non-melee LB should be used, that it's addressed before the fight begins. Also, if there's a specific time when I should use the melee LB, I usually mention it before the fight (like in Brayflox HM, I'll say before the fight that I plan to use the LB to kill the boss before the last bomb phase).

Communication is key, people.