Sword of Spirit
Legend
Jeremy Crawford's suggested alteration for those concerned with the amount of out of combat healing that healing spirit can muster stealing prayer of healing's thunder, is (if I recall correctly) to limit it to Proficiency mod X2 uses. That seems to work out fine (up to 5th level--which is what matters the most, because you aren't normally going to be upcasting 2nd level healing spells into high level slots) if the spell is cast with the proficiency bonus you'll have when you first get the spell slots. However, if you look at it with a +6 proficiency bonus, it doesn't work so well. By 5th level you are outclassing prayer of healing in pure hp healed for a party of 6 (worse with smaller numbers), and you can potentially use most of it on a single character. So, still unsatisfying for those who care about that sort of thing.
I played around with a few different options and finally came up with one that gives really good numbers (and works even if you upcast it above 5th level).
Maximum uses = 3 + Spellcasting modifier
It feels a little better than my runner up of Spellcasting modifier X2 (and I think it gives better numbers). I can't think of any precedent for that formula in a spell, but I'm pretty sure there are precedents for that formula elsewhere--which puts it on the same standing as far as precedents as Mr. Crawford's formula, and ahead of my runner up formula.
I played around with a few different options and finally came up with one that gives really good numbers (and works even if you upcast it above 5th level).
Maximum uses = 3 + Spellcasting modifier
It feels a little better than my runner up of Spellcasting modifier X2 (and I think it gives better numbers). I can't think of any precedent for that formula in a spell, but I'm pretty sure there are precedents for that formula elsewhere--which puts it on the same standing as far as precedents as Mr. Crawford's formula, and ahead of my runner up formula.