Confirmed it won't jump when all are full health.
I've been playing around with it a lot lately, trying to make a full font with the heals.
(not for typing, just for show in game or use it as some intro to a movie I'll probably never make )

I myself have them CH on a hard-coded target for combat if I have no healable target.
It has my preference,
because a char getting hit is usually the one needing the most and fastest heals,
if they would heal themselves they could get interrupted and only get procs to heal them.