Not sure if this is a bug or working as intended but…
I can simply teleport into a group of mobs, channel focus, and have elemental nova triggered by attacking mobs which because I have converted it to a channeled skill on the skill tree it will run indefinitely, and because I am channeling focus I will not run out of mana. So can permachannel elemental nova.
I have 19% chance to trigger elemental nova from idols.
Same with Fireball proc’d from Flame reave if you are casting focus when the proc occurs. Haven’t check if this is consistent with all channeled abilities or just focus - disintegrate should be able to replicate this.
I think this is caused by skills that can be converted into channelled skills and have some other method to proc the skill, so I wouldn’t expect it to work with Disintegrate since I don’t think there are any other ways to get Disintegrate to be cast by something else (such as an idol that procs it on hit or when hit).
confirmed it can be used during disintegrate channel, meaning that the bug is non specific to which ability is being channeled and which ability is being proc’d.
On a side note, this does make disintegrate one of the best builds in arena when plugged into void sorc. Perhaps that 17% buff was too much