Range Hood vent penetration in RPanel style roof?

We have an existing Galvanized R Panel style roof, (the corrugations are 9 inches on center so not exactly R Panel), and need a roof penetration and roof jack/cap for this new vent hood we are installing with a kitchen remodel. All of the vent hood roof caps seem to be designed for shingle roofs, and we are having problems finding the appropriate roof cap for this situation. The hood is 600 CFM with a 6 inch diameter duct. The roofer from my contractor has quoted a 4 inch diameter flue vent and cap as a solution? Any suggestions are welcome.

If you can get the duct to penetrate the roof at a corrugation, you should have plenty of room to put a rubber roof jack in without blocking the water flow. If the duct hits in between corrugations, then I would put a pipe curb in and then the rubber roof jack. See the attached picture for an example of a pipe curb in a standing seam roof. It would be similar for your panel. You can get a curb company to make you a pipe curb. I would suggest LM Curb out of Longview, TX