I don't know about that. Sounds like a good way for a programmer to go bald. And I think it would be a nightmare to maintain.
I agree about it being a maintenance nightmare. Using multiple versions of dojo should never be a long term solution. It's feasible for quick, short term prototyping but for anything beyond a proof of concept, I wouldn't recommend it. The old "just because you can, doesn't mean you should" cliche applies.