There are a few topics in the forums on the subject of the KA and this topic has been hashed about. Generally, I think most are doing top end between seasons (12-16 hours), however, they can probably go further. I had mine done at 12 hours and it honestly could have gone longer but it was the end of the season. I believe the thinking is bottom end every other top end.
As for the case, I don’t think that subject has come up. I think these motors have been around for 4-5 years in the US, I would be surprised if that has been required at this point.
Compared to the KT100 these motors are very reliable, durable, and more powerful. Unlike the KT my experience has shown that if you are too lean it just doesn’t seem to run well whereas the yamaha would run good but overheat or worse.
Run 16:1 mix, even though the manual says 20:1