Problem manipulating Searing Arrow attack range

[Pinzu]

I'm trying to create dynamic attack range using Searing Arrows to manipulate the range. I've changed the Hero Attack Range to 100 the problem is that after a certain range the unit will perform the attack but no projectile will be fired.

Another issue is that it doesn't work as intended with auto-cast, I suppose this has always been the fatal flaw with trying to manipulate it this way.

Anyway to fix this?