It's not realy handy if healers dps is lower than yours, but i can't resist help on healing also. only trying to do it on 50% or lower something like that (or when out of combat.)
Casting it will cancel your dps
But whatever right
don't have to be optimal on outgeared stuf doing chill routines.
It gets funnier without healer on +6 i once noticed ;p one left at half way through a dungeon.
It's kind of tight schedule and need to actualy think what to cast when.
Same for higher content ofcourse, i rather leave the healing to the healer then
Or help in some extreme cases.