So one thing I've noticed, especially in the higher levels and underdark, is you're going to need to long rest a lot. This can be tedious since all of your buffs fall off once you do. It would be nice to have spell states, where once after you long rest, you're able to set up your buffs and then save a configuration. Then when pressing this, the characters automatically set up the buffs in one click rather than many.
This would go for summoning familiars, using buffs like mirror image or aid, etc. Just a QoL thing, but would seemingly be really useful.