I tested the purge from Curse-eater with Forward Momentum because I heard on the forums that Curse-eater was good on magblade, and especially melee magblade. I tested it and found it pretty bad on destro/resto magblade although that was last patch when magblade overall was pretty bad.
I thought it was perhaps that the initial heal of Forward Momentum counted as a direct heal unlike the initial heal of say Rapid Regeneration. Instead whenever a Foward Momentum heal ticked it would proc the removal of negative effects. First tick, fifth tick, etc whenever it would tick it'd be able to remove negative effects if Curse-eater was off cooldown.
Never actually used it but I also didn't take the time to report it as a bug other than telling zone chat about it and asking if anyonee else knew that it was at minimum buggily working with the Forward Momentum HoTs.
Since ZOS pretty clearly stopped Curse-eater from procing with most HoTs this behavior is surely unintentional.