I use EFF and am generally happy with it.

However, my followers are OP b/c they are essential (custom NPCs made that way in CK). I made thm that way b/c I was tired of them getting killed by getting in my way and / or charging stupidly in ahead of me.

I wish there was a mod, where follower NPCs would be essential, but would go into bleedout and just stay there until I gave them a healing potion or used a spell to do so.
They would still be essential, so the don't die, but they are out of that fight.

This is the only thing I wish would be improved.

That would prevent them from becoming essential tanks, but also preserve them from doing stupid Combat AI tricks. It would also improve the utility of healing other spells and potions.

I've looked at CSR, but it is a Mercedes, and all I need is a Nissan that does this one thing.

No spoilers, but if you are planning on getting Dragonborn there is a little something thrown in that doesn't work as you describe, but you may still appreciate when you find it.