Looks great and I may well give it a try. I have one question though which I can't seem to find any mention of from the site - is there any way to define breakp

Looks great and I may well give it a try. I have one question though which I can't seem to find any mention of from the site - is there any way to define breakpoints for responsive layouts? Speeding up laying out elements is really nice but it's difficult to communicate responsive designs to production without having to duplicate artboards.