Ah ok, didn't realize you could define focuses that way. I guess that the wall (or whatever) acts like an object of opportunity? Could I take Immobile limitation? Doesn't seem like a GM should allow it as its not much of a limitation because I'm still able to go through the gate myself and once I'm through I wouldn't care about having to bring the gate with me.
Just realized on page 223 of 6e1 there's a "gate to hell" example that works very similarly.
This is what I'm thinking
EDM (1 location), AOE 2m (+1/4), usable by others (+1/4, 2x (1/4 more) but 1 at a time (1/4 less)), constant (+1/2), end only to activate (+1/4), safe blind travel (+1/4), Active Points: 50, Gate (-1/2), extra time - full turn (-1 1/4), gestures (-1/4), OIF (-1/2), Real points: 14.