I guess I'm  pretty masochistic, i was made to do both from a young age.  Never gave up on it either. 

what i'm saying is you don't need to be an expert at both but some understanding and basic training on the design side would surely make it a lot easier to coordinate with the technical. i keep hearing devs complain about the designers they work with......

and i often think huh, if they only understood the gap. but that only happens when you train both sides.