While it's an unfortunate cheap out across most manufactures, you should consider installing Borge dully valves. They have to pull your tires (good time to install balancing beads / bags/ sand) but you will have a custom designed valve that is easy to access or yo install TPMS on. You will need a truck tire shop to do the install. Extenders are a recipe for failure over time.
'16 Coachmen Mirada 35BH
Formerly 31FK 15 Grayhawk
Toad: 2015 Jeep Cherokee "The Caboose".
Taking in the sights wherever my Trolley takes me!