I have used Renaissance wax on a polished sculpture that has kept it from tarnishing but not on photographs. I print with platinum/palladium on papers that have some "tooth" although they are smooth papers and I wonder how applying and buffing the wax would work? I don't really see any need to protect the print since p/p has great archival properties. You may want to modify the emulsion or negative exposure/processing to increase the blacks.
Jeffreyg