normal runing while casting

By using Bonestorm skill I found that when you start casting it for brief moment and got back to casting it again I am able to run normal speed while I`m casting it, just before animation of first bonestorm should drop projectile. I think that this method is possible with every channeling spell.

That also showed me that there is a place in this game for skills that can support some time threshold for some additional effect ;D meybe as support gem