Yeap, not proccing on dots, just tried it, if it didnt proc on 4x corruption in 3 minutes it sure wont proc on others.
It did proc when i started shadow bolt spam so it's direct damage only.
DFO sucks anyway, yea, nice haste on it, but the proc is underwhelming, especially if you gotta move and it procced 16s before that - rip the final (and the only worth) stage of it.
And according to
this guy, it seems to be meant that way, good thing is it can proc from channeling so that means MF should be ok and from casting a dot so each time you do VT, or if you gotta manually refresh SH:P.