Hi Bebop
Just noticed your post. I used to use a 9000pro to control a KN1500 with no problems so you should not have any with the 9000 and KN7000.
At one time a few years ago I had up to 6 keyboards midi'ed together without any tuition and only one or two of them blew up !! It almost certainly accounts for my rapidly declining mental faculties but at least now I don't have to arrive at gigs 3 hours before I'm due to start.

All the best
Trevor