I wish BA did more "experimental" fights. Like in WoW (legion) where you had "challenges" (scripted solo PvE) for tanks, healers, aoe DD, single-target DD. I can see such concept working here too. Like, why "TD commission" only yellow-colored? This makes no sense. Same with single-target ones. Make healing commissions, make movement-focused ones (where you need to dodge, instead of eating all damage), and etc.
I understand that, PROBABLY, that's what raids are for (greg, black dog, etc). But...i dunno. I think it would be very easy to make new modes.