"I don't see how any warranty issue comes up at all... All AJ has done is software related. Loading new styles and sounds and a tweaked OS should have NO impact on any hardware issues."

Let's say a part time / under contract Yamaha or Korg engineer/product specialist bought keyboards for wholesale prices and had them shipped to their home. Then that same employee modified the keyboards and resold them with a longer warranty.

This would never happen with Yamaha or Korg.