The unnerfed healing spirit is totally busted. If you don´t think dancing around the spirit is more than dumb*, ok.
The nerfed one is also dumb. Just not good enough.
I think the best thing is just scrap this spell. It does not fullfill any role. It is either totally rules lawyer expolit or just a bad spell. chose one.
*because it is just way more powerful than any other spell and uses the congaline mechanic which is totally dumb. If you want healing to be more useful, just make all spells better and don´t rely on mechanical exploits.
There are a lot of different angles here, all tossed together like they are the same thing.
1) No one, to my knowledge, has every claimed that the Healing Spirit spell is busted in Combat. You also can't congo-line in combat. Not without the kind of shenanigans which make the need for that much healing... questionable.
2) It does fulfill a role. It is a Heal over Time spell for the Primal casters, increasing their ability to heal beyond just cure wounds and healing word. It was also a better healing spell for Rangers, who greatly benefited from it. Those are plentiful in terms of role.
2a) Before complaining about it making Rangers too good of a healer, note that the Paladin gets Aura of Vitality, which could be compared favorably to the spell 2d6 per round instead of 1d6, costs a bonus action, but just has to be within 30 ft of the front-line (where most damage is taken) instead of in a specific 5ft square.
3) It is more powerful than other healing spells of the same level (if used out of combat and targeting multiple creatures), sure, it is. I also think just about every single healing spell is
too weak. Therefore, arguments that this spell is stronger than the others isn't a convincing argument for me. I want more healing spells that are stronger than what we have. Instead of nerfing or banning healing spirit, I would prefer to keep it and raise the other spells to a comparable level.
The most powerful thing I've ever seen the spell do, in actual play, was heal a barbarian and my druid who got wrecked in a combat, back to full, out of combat. And again... shouldn't using one of my most powerful healing spells allow for that? That's why I was playing a druid focused on healing.
Making sure they don't go down in the first place?
So, instead of making it incredibly difficult for PCs to die, you want healers to make sure they don't drop to 0 hp and risk dying... Isn't this a bit like saying that you don't want a cup of water, you want a cup of Dihydrogen Monoxide?
I'd like to buff healing a bit, or at least have them scale better with spell level. Cure wounds can easily start at 2d8+wis and add 2d8 per spell level. But as I said, I'd rather have them unlock the characters ability to spend healing surges mid battle.
Don't disagree with any of this.