The numbers dont lie, BUT:
It's mostly the oxygen that permeates thru the rubber, so, if a nitro-filled tire doesnt have that 20% oxygen, it wont lose pressure as fast as a tire that DOES have oxygen.
Its a simple idea that eludes ALL the youtubers who unequivocally state that its a rip-off.
It is not a rip-off. Millions of miles of lower tire wear and avoided tire blowouts on commercial trucks prove that. Large fleets don't keep spending the money on something that does not prove itself.
Now, would I recommend that everyone go get their existing tires filled with nitrogen? Of course not. I dont do that either.
But if the tires come that way, its a feature, and does not add much to the cost of the tire when filled at the factory (or dealer).
One constant in the RV community is tire failures, usually traceable to lack of attention to them....letting the tires slowly lose pressure, and/or tires that are aged out and prone to failure.
If you can stack the deck slightly in your favor for little or no additional cost, why not do exactly that?