[lynaghk]

The runtime engine already free for non-commercial usage: https://github.com/lynaghk/subform-layout/blob/master/LICENS...

Or am I misunderstanding your question?

Re: designing for the perfect scenario, I'd say devs are guilty of that too --- I'm in Australia right now, and it's obvious when an app or site has only been tested on localhost =)

Specifying dimensions in the "application state space" along which to vary is a tricky problem. It's not clear to me how much of that can work in a GUI tool vs. programming languages and stuff like Clojure.spec, property-based testing, concolic testing, etc.