Interesting idea. But would it have to be part of a Main Quest Delayer? As far as I know, those MQDs you're speaking of simply need you to be put in jail at some point during your journeys. So wouldn't it be possible to simply make a quest mod that, at some point, has you framed for a big theft or something and sends you to jail?
Because if that were the case, there might be already some mods around that do that... although I don't know of any. But anyway, if there's no need for it to be part of a MQD, more modders might pick up on the idea.
(For the record, I believe that there is at least one alternative start mod that doesn't require you to go to jail. You pick up the amulet from the body of the prisoner whom the amulet was given to by the Emperor.)