I'm really contemplating switching to Vuhdo.
Fewer addons is preferable to more addons.

At the moment, I'm using Grid.
And then GridCustomLayouts for an alphabetical sorting.
And then Clique to interpret my clicks.

With Clique you can set it to heal on a single click.
I've set normal left click to not be a heal, so my priest can actually target another toon, to trade with them for example.
But Alt-Left Click, Ctrl-Left Click and then Right Click or side mouse buttons each do whatever.

I'd hope Vuhdo would allow one click = one heal.
And not require click = target, 2nd click = heal.