Getting a residence permit doesn't (as a general rule) require entry on a Z visa.
All the regulations I have seen state that (as a "general rule") entry has to be on a Zvisa.
I, also, have had 'nth' Residence Permits issued without going through the Zvisa process. Once in the country, a different procedure is in place for 'renewing' a Res Permit.
I, and I would say many others, would be interested in your answer to the question posed by old34.