So I originally wanted to try to figure out how support for external libraries/variants should ideally work, but in trying to do so, I ran against many little walls in the current API:
The only/main code is in jquery.module and is mostly a quick hack only. However, I've added plenty of @todos in the process.
As most of those issues are revealing fundamental problems in the current API, it would be wise to focus on them first; i.e., before trying to add new features to the API.
It's possible that some @todo issues are covered by other issues/patches in the queue already. We'll have to figure out the order of @todos to tackle, and which of them should be tackled in a separate issue.