In order to make BR work like a charm, take from the predecessor, FFXI.

Make BRs auto-initiated by the conditions of actions.

If you use a weapon skill, like skewer, then someone uses an attack of the same element or any other specific, then it triggers the BR and causes additional dmg or an extra animation or effect of some kind.

Essentially speaking, rework BR to be more like a skillchain, or renkei.

The problems ive had with BR were hitting the br button, then queuing pt members to attack, then hitting the button again. To make it more fluid, just take out the button and make it auto-initiate like i've stated and it will get rid of the confusion. There will be charts that come out, and people figure the combos out just like with renkeis/skillchains, so to think its to hidden is not likely a viable cop-out.

Very simple, minute change to make execution more fluid. Reminds me of street fighter and some other games where you have certain people together and do a special attack, yet the execution was never this stubborn. Yes we can set macros and what not, but we honestly shouldnt have to.