I never realized you were that far up. DOH!
A rule of thumb for the main is 1 size per 1000 feet gained in elevation. You ever look up the stock high altitude jetting for the bike? I cannot seem to find it anywhere online.
I'd start at the pilot by one size down. Tune that circuit. Then on to the needle/needle jet. And then on to the main. Until the bike runs well.
Man I missed the most elemental part of the equation. My humble apologies.