I don't know that target aliasing works in your scenario, using Project to Surface. (I've never tried to use it in that application.) It should work for end condition component targets.
As a quick solution (just to determine as quickly as possible if it works for you), create an end-condition component that seeks <Active> (or whatever label you're trying to use here, but I guess active) at any slope. That should find whatever is in that alias list. From there, sort out how you can make that work for you.
As a quick solution (just to determine as quickly as possible if it works for you), create an end-condition component that seeks <Active> (or whatever label you're trying to use here, but I guess active) at any slope. That should find whatever is in that alias list. From there, sort out how you can make that work for you.