If there is nothing supporting the braided extender, then I would want to support it. For the outside tire, if you can't reach in between the tires to screw on the TPMS then you need to get a short extender to bring the valve out to where you can reach it.

Yes it is a pain to install the TPMS and extenders and to keep the extenders from leaking, but I wouldn't drive or pull an RV w/o a TPMS.

When traveling, about every hour or so, manually cycle the TPMS monitor through all the tires to check for any pressures which are significantly off from normal. Normal being what they are after about 20-30 minutes of hwy driving. In warm weather (85-100*) my tire pressure goes up 10-20 pounds from cold (70-75* in early morning). So if I started at 80psi and in 95* outside temps my pressure is now 93psi, my tire pressure is going to have to drop 23% to 25% before the TPMS is going to alarm instead the 10% to 12% the TPMS is set for. Additionally if all my tires are around 93psi while traveling in hot weather and now I see one tire at 98psi, I know something is wrong. Something is making the tire heat up. Could be a slipped belt and and chances the tire will blow before too long. Keep in mind the inside dually will be hotter (and therefor higher tire pressure) than the others. Usually 2-5 psi higher. Lack of air circulation causes the inside tire to be hotter.