Thank you for sharing your idea.
Unfortunately, such backward import isn't possible. There is no unified way how to define migrations/models.
Unfortunately, even in Doctrine2 where annotations are much more strict we are not able to proceed with such continuous import. The problem is that not everything is 1:1 between the model in Skipper and exported target.
Some time ago we tried to implement such behavior but this led to a lot of conflicts during every import. So we enabled only one-time import during project creation and after that, it's necessary to edit the model in Skipper first and then export it.