Any reason for this design decision? It just makes it harder to manage procedural meshes. Unity has this functionality out of the box, see this.
I implore you to allow cooking at runtime in a more easy fashion than this roundabout way. At least provide an optional module that we can link to allowing cooking.
I have started a Feedback thread on the subject, as I am disappointed in the direction you are taking.
EDIT: James as responded in the Feedback Thread on this subject, and it is good news.