Guidance pertaining to healing and restoration techniques from the Technique Guide is as follows:
HEALING AND ENERGY RESTORATION
Healing and Energy Restoration techniques can be created and will operate on the following logic. They must be derived from the PRE stat.
HP and Latent ENR
HP and Latent ENR will be restored on the basis of 1/2 the stat boost provided to the Technique.
Example: Base PRE stat: 40 + 40 (Honed Technique) = 40 HP restored.
Mastered ENR
Mastered ENR will be restored with the full strength of the Technique. If restoring your own Mastered ENR, then you will still have to pay the associated ENR costs for the Technique which will be subtracted from your net recovery:
Example, cast on an ally: Base PRE stat: 40 + 40 (Honed Technique) = 80 Mastered ENR restored.
Example, case on self: Base PRE stat: 40 + 40 (Honed Technique)/2 - 25 ENR to cast = 55 Mastered ENR restored.
A Persistent Healing Technique... hmm... as in you can take healing actions on your turn. So that would work on the logic of converting your Basic ATK Action into a healing "attack," so you would be able to "attack" your allies and heal their HP for your (PRE DMG + Tech Modifier)/2.
Sound reasonable?