You're picturing the residential-construction kind of general contractor; but there's also the commercial-construction kind: the kind who works for a commercial

You're picturing the residential-construction kind of general contractor; but there's also the commercial-construction kind: the kind who works for a commercial construction company; who interfaces with a property developer as client, and with an architecture firm that the property developer has also contracted; and then either works with an structural engineer working for the developer, or for the architecture firm, or with their own structural engineers, or all three. All of those engineers push back on any impracticalities in the "dream and vision" before any of them are willing to sign off on it — where that sign-off is a requirement before the general contractor will get to work. That's the thing that I would expect here: that the firm you'd hire would come with a built-in person to look at your design and say "no, this isn't gonna work, try again."