Running Honda EU generators re-jetted at high altitudes.

I re-jet every time we go up in altitude. Gens run like they should at sea-level. I have the two high altitude jets. 5000-7500, and 7500 to 10,000 I think. Swap takes about ten minutes when you get used to doing it. I put a tag on the handle to remind me what jet I have and to NOT run it a sea-level with high jets. Yamaha does not offer high-altitude jets. I called the Tech # and the guy said it didn't matter, all air is the same! I bought Hondas. Chino