I'm using Grid + Grid Custom Layouts + Clique for healing.
I have a repeater region over the first column only.
Which lets me heal the party from any toon.

I've also gone into the Clique settings and set the clicks to only apply to my Grid frame.
So I can still left/right click on a toon or their portrait in the target box for trading.

In mass pvp, I lead with the Paladin always.
So can click heal anyone on the grid frame.
In questing or whatever, which is only my five... I can heal anyone in my group, from any screen, without a massive repeater region.