For the record, I don't need anything like this.

I was just wondering if there would be any technical obstacles; so far, it seems that chainline would be the only one (I don't think that keeping it tightly secured would be any more of an issue than with any other crankset and bottom bracket [as long as there's an inner shoulder to keep the crank arm from sliding inwards]).

Of course, it's also nice to hear from those with more sense than creativity.