Something I've been thinking about as an alternative would be for healing spells to do minimal healing, but allow the target to spent whatever HD they wanted when they are healed. So like, Cure Wounds heals the warrior for 1d8 and let's that warrior spend whatever HD he has available immediately. Make Cure Wounds a bonus action so that the healer can be doing something offensive, and it might be pretty balanced.
In combat heals would have the potential for being huge and life-saving, but at the expense of down time healing.
In combat heals would have the potential for being huge and life-saving, but at the expense of down time healing.