Stop air from using waygates!?

Here's the deal: I got a couple waygates in a triggered system I'm making, now I want to stop air units from using them.

Plan A) Setting Targets Allowed of the 'Awrp' ability to only ground: didn't do anything

Plan B) Placing Air Pathing Blockers directly over the waygate: also prevented ground units from using the gate, I figured the air blocker also blocked the LOS of ground units making them unable to "see" the waygate

Plan C) I figured that the pathing blocker used the LOSBlocker model as model so I changed to model to none: didn't help

Plan D) I figured that the pathing map of an air blocking area should actually be green, not teal, so I made a green .tga and specified it as pathing texture of the blocker: didn't help

Ok, any other suggestions how I could stop the air units?
And no, I don't want to mess with triggers that will stop them as soon as they come close, as I want them to carry out their orders ignoring the gates.

Strange, in all my melee experiences, flying units already ignore the waygates and move to the destination on their own.

Block their orders to go to the way gates to the hell.

How would you do that? Note: In any case if the way to the target of an order will be shorter through the waygate, they'll use the waygate (you don't have to click on the waygate for it to be used), therefore blocking orders is not an option because I can't even know whether they'll use the waygate or not.