Jerry's already stated pretty firmly that he will not be writing any kind of visual layout editor or layout mockup features. Honestly, I really don't think it's that hard to go "okay, I just checked Debuff Type: Poison to show on the Frame Border indicator" and use your imagination to envision a green border around the frame. About the only things I see any kind of need for advance viewing of are icon size and corner size... but even those you can easily test by temporarily assigning a self-buff to those indicators and applying the buff, and if you forget to do this, they take about 5 seconds to change, which means you have plenty of time to change them while you're drinking if you don't like their current size. If you absolutely can't imagine what a bright green border or a big icon in the middle of the frame looks like, just queue up for AV.
Oh neither do I, I was just throwing ideas out since there were requests on how to configure Grid2 without having the menu structure as it currently is in Grid. I actually don't mind the current menu structure as all :)