Yeah, but if the character swapping in is at max BG you've just net lost 1 BG because the additional one will be wasted with nowhere for it to go. I can continue my combo by using a Break Soul, and the majority of the time I feel like using my BG is best for a Mystic Arte. I've found it hard to combo off of the swap-in attacks too because they seem to have a long-ish cooldown at the end of them and half the time they come in and overshoot the enemy or go off in the wrong direction entirely. The only time I find it generally worthwhile to swap out a character is when the one in battle is likely to die.
Further the equipment enhancement system I find entirely broken (which seems to be the primary way of getting a meaningfully higher maximum BG) due to the scarcity of certain types of materials (Bronze/Silver/Gold scraps and their corresponding equipment seem super rare compared to the other types), not to mention the near constant need to be swapping gear to make use of mastering all the equipment skills. These things mean that trying to keep all the characters in a cumulative +5, +15, +20, etc. of enhanced gear for the max BG bonus is pretty much an impossibility for me, and I'm 45 hours into the game in mid-Act 2.
