One thing about BG III that still bugs me is the concentration requirement for certain spells. In the older games you could cast blur on yourself, launch a cloudkill, and put a hold person on someone else and have these all going at the same time. In BG III you can galide with only one of those three to concentrate upon.
That's not really a BG3 thing but a 5e thing. It carries over from there. Most non-instantaneous spells in 5e have a concentration requirement to keep them going.
