Thaumaturgy heals will now provide a bit of energy to the target (lessening fatigue) as well as healing wounds. Also, the more thaumaturgy you are channeling at once (preparing thaumaturgy multiple times), the more energy and healing the target will receive per cast. The energy gain is only slightly more than the energy cost, so restoring one's own energy this way will be grossly inefficient. The intention is for it to be used on others.
Keep in mind that it tends to balance out with the extra fatigue of channeling more thaumaturgy at once, so while it is overall more efficient time-wise to channel more thaumaturgy for more powerful casts, the channeler is still expending the same amount of energy - they're just accomplishing the healing in less time.
Oh, and the heal got a slight cosmetic upgrade as well.
Thaumaturgy heal changes
Thaumaturgy heal changes
[#GMCHAT] <Mirazia> I think you're enjoying this [mighty winter stuff] more than you realised
[#GMCHAT] <Rias> I AM AND IF THAT'S WRONG I DON'T WANT TO BE RIGHT
[#GMCHAT] <Rias> I AM AND IF THAT'S WRONG I DON'T WANT TO BE RIGHT