Here's why Star Sapphire should not be a healer.

I did say "beyond basics". And you can't think of a power for 1 faction and ignore the other, that's not how the game works. Another thing is since Indigo is a NEUTRAL corp, that means they can be used by both villains and heroes alike, regardless of "mind control" which wouldn't work on exobyte-infused metas anyways.

When it comes to a Green Lantern ring having to be near a Blue Lantern to activate its full capabilities (I could be wrong here), the comics haven't specified distance. In the New Guardians comic I think it was, where the Reach was decimating the Blue Lantern homeworld, Kyle Rayner had just entered the planets atmosphere when the rings activated (he wasn't right beside them).
As a way to be consistent with the lore, and we are all based in Gotham and/or Metropolis with 1000's of Green Lanterns, I would think this would be a way around the blue rings capabilities.

I know how the game works, I'm just trying to think of something for the game. I know that, I'm pretty sure everyone does by now. Considering that the ring does that for villains, and I have yet to actually hear of such influences of the exobytes from the devs, Indigo is a viable option.