I haven't seen anyone else use the EDFC on other coilover systems, but from what I've seen of the EDFC itself its simply a remote display and control for four motors that turn the dampening knobs.
Theoretically, if you could find a coilover that uses the same type of knobs as the TEIN, or modify the knobs or motors to fit - it should work the same. Being that it seems that no one's done it, don't take my word for it.
IMHO, if you're going to spend the extra 300$ to get the EDFC why not just get the TEIN SS without it first. Save up then buy the EDFC if you *really* need it a couple months later.
You might find that you won't need it. As in, just set dampening at a good setting for everyday driving. Then when you *know* you're going to go to a driver's event or race that day, turn them up to the appropriate settings for that particular event.
My two cents.