l3backend: adding new DVI specials?

[Karl Berry]

         \special{header=l3backend-dvips.pro}

I admit I don't understand. So this \special is output unconditionally?
How about only emitting this \special if the backend is in fact dvips,
instead of expecting every other DVI driver in the world to be changed
to recognize it? (Especially when it's merely to be ignored.) I'm sure
you thought of this, but ... I don't understand. --thanks, karl.