I may was understand bad what u trying to post here, i think i got your point (my bad).
You say that maybe it should speed the heals, cuz every time MG deals dmg, corruption deals an extra tick with arround 30% dmg, it counts as a corruption tick, which should be 1 extra heal tick from the gliph cuz corruption is doing dmg
I can show this with recount: https://www.youtube.com/watch?v=fS60xzZpaNY , http://imgur.com/a/c9des
20 ticks from corruption (dot) which is the normal debuff dmg
11 ticks from MG, the ones with 30% instant dmg every time MG deals dmg
so if this is true the Corruption ticks provocated from MG are not healing the lock atm, which would be a bug: https://www.youtube.com/watch?v=fS60xzZpaNY
here u can see that just normal ticks are healing from the gliph, but not the corruption ticks from MG, but are counted in game as Corruption dmg, so it should heal ye
(it heals 64p from something, idk what is that)