sounds like there is a discussion about apples to oranges…
Nitrogen in tires is 100% (or near) pure nitrogen.
Air in tires is air (mixed gasses) and water vapor.
The water will expand more than the gasses is what I found on a quick INTERNET SEARCH (never use gaagle).
Using this pure nitrogen gas must have a reason. Race cars, airliners use it. Nitrogen is used in racing shocks.
I guess you could use pure oxygen, but then you would have bigger dangers in the tire.
I guess you could try to dry out the ambient air you are putting in the tire first???
This seems a bit complicated topic for RVs