I can confirm we don't have the 02 sensor, I think Asia and European bikes are the only ones which do. Most likely for emission standards and kinda sucks if you ask me.
As for the flash being invalid, I couldn't really say not my area of expertise. But here's what I think and that's just an opinion.
1) The big improvement from the flash is the Secondary Flies opening sooner. I assume this would be the same on both types of bikes. The tweaks to the maps are minor, and if you have the O2 sensor then in theory the bike should take care of that itself. I think.
2) Someone would have to call Don and ask if he saw O2 code in the ECU. Assuming he didn't look, then someone should look up the ECU Part and see if its different on the US bikes vs Asia/Europe. If its a different codebase/flash then it should be a different part to denote it.
3) Assuming its the same....then the big question is.....could Don hack it and enable us to add our own O2 sensor like you do with the Autotune. That would very cool!!!!! But I'm sure that's a pipe dream.
Or someone could ask Fred Harmon on the COG Forum, who's the expert on all this stuff and he probably could call b^!!sh!$ any of this.
The microfiche on Bike Bandit shows 3 different ECM's 21175 A-C
When Don flashed mine I had the option to change:
RPM limit
MPH limit
Fly's open sooner
richer map for aftermarket pipe
On a Europe model the first 3 options would still apply, but with O2 sensors the mixture takes care of itself.
And YES it would be cool if Don offered the option of adding O2 sensors to our bikes.