Even though healing magic doesn’t exist, and Regrowth seems to be the only way to restore the Eidos. Magic causes a temporary change in reality.
So for an actual healing spell, could one in theory, use Magic to temporarily increase the cellular metabolism of the target and there for cause their body regenerate quicker. Even if the spell ends, and cellular metabolism is returned to normal, the healed tissue would still exist. This could be used as Emission Type Magic, since it involves subatomic particles.