Metal vs rubber or plastic extended valve stems have been discussed several times around here. The vast consensus is never use plastic or rubber valve stem extensions especially if you are going to use pass through external TPMS sensors. The slight added weight of the sensor will cause the plastic and rubber extension to vibrate excessively and even worse — break. When they break the first corollary to Murphy's Law immediately comes into effect. Remember too the inner rear wheels are steel and the outer ones aluminum, so you have to have metal valve stem extensions that are specific for the different metals. The Dl1spal]DL1SPAL Chrome Dually Valve Kit
set has the right materials for both the inner and outer wheels.
From the posts on these forums, it also appears there is a preference for pass through
external TPMS sensors. You do not have to dismount the tires to install them or change their batteries and the internally mounted sensors often have their signals blocked by the wheel itself. I even put external TPMS sensors on the wheels of my tow dolly and the rear wheels of the toad itself. I did have to use the long range
antenna on the readout to reach the rear wheels on the toad.