Need mappable (or at least present) "Save As.." keyboard shortcut

We need a way to remap Cmd-Shift-S to what it is in In a vast majority of apps! Cmd-Shift-S is "Save As..." dag nab it!! Sadly, it's "Save All" in MockUps with no chance to confirm.... so if I've made some changes in a few mock-ups, and want to save ONE of them as something new, out of habit, I hit Cmd-Shift-S... and now I've overwritten however many files I have open. This makes me sad. I assume you guys have it the way you have it for a reason, but I can't be the only one who naturally expects that to be the Save As.. short cut in a design app, right? At the base minimum, can you at least out in a shortcut for Save As... ?? Maybe I can retrain myself for this one App =)