And here are the crunched numbers. Used GPS speed data to calculate acceleration, instead of the accelerometers, otherwise pretty much the same methodology. Significant improvement from changing the plug and maybe a little better with downjetting too. The BR8ECM data was with a strong headwind, for whatever that's worth.
Oh and sometime around when I shot that video, the rear mount for the pipe failed... the braze held, but the steel tab broke. And I think my header o-ring might be toast, so may have a header leak. Time to order the real-deal KTM o-ring and not use Harbor Freight (hey, I wanted to get it running!).