Currently, disintegrate triggers sun and storms ward only on initial cast. With 3 points in silver rune, this means that the player could potentially generate ward every second by restarting disintegrate, but that seems like it should be discouraged. Instead, shouldn’t channeling disintegrate count as casting it continually, thus triggering sun and storms ward generation as often as possible?
No, that’s not how it works. For channelled skills “on use” is when you start channelling.
That would be really inefficient, just like resetting campaign zones to farm chests by going to town. Just because you can do a thing doesn’t mean it’s particularly effective or a good idea.