It's just an idea I though of: can't we get/put ofw/cfw to/from the ps vita, by exploiting the "Restore the PS Vita System" option in the "Format" menu?
To restore the PS Vita system, it has to get the files (if any) from somewhere. If we (by an exploit?) can change that specific file (or dump it?), next executing the restoration, we can get CFW on the PS Vita?