Welcome to the forum, and congrats on the new Pinnacle, can't help you with this location of vent placement, but have also read up on the same question on past discussions. Some have placed vent out the side wall due to heat and moisture collecting under the gooseneck. With the correct covers, it looks like a factory job. So good luck with the project, I'm sure you will find some input here. Cheers.
2015 Pinnacle 36REQS
2010 F-350 Harley Davidson 6.4L Powerstroke
Short Box Crewcab
6" Procomp Suspension Lift & 35" M/T Toyo Tires
Doug & Nikki, 2 fur babies
Murphy & Chloe are Shar Pei