I'm trying to build an adaptive curtain panel family with an intermediate mullion that stays vertical with the project coordinates, or orthogonal with the project z axis. I can get it to work with a rectangular panel but as soon as I apply the panel to a non-rectangular grid it no longer works. Setting the adaptive points to global (xyz) does not work because the z axis in the project does not match the z axis in the family. Any suggestions?

I've attached a few example pics. This is just the vertical mullion component of the family. The 3rd attachment is a little hard to read with the gigantic coordinate diagnostic tool but you can see the non-rectangular shape's panel's coordinates do not match the others for some reason.

Thanks in advance.