Thanks for the info about the Kawai MP11SE, it brings back memories of the first synth I ever bought myself (versus borrowed from a family member), the Kawai K5 I bought in the late 80s. I looked it up the MP11SE and it looks outstanding. Still to this day I wonder why new synth key beds don't feel as good as that K5 I had did, it was just something special under the finger tips and it sort of spoiled me for how a key bed should feel and respond.
Ergonomically, a lot of controllers would be different than the situation I described. The Keystage is a wonderfully-freakish "slim" keyboard, so when the Bree is in the tray, the distance from the outer edge of the white keys to the lowest knob at the bottom of the sloe on the Bree is about 8" away, with the tray putting the filter EG1 Mod knob of the Bree about 9.5" away. The slim form factor of the Keystage 61 is a bigger reason (for me) for getting it than even the poly aftertouch, because it is not in my primary studio room, it's a smaller "impromptu" studio in a different room with less space. If I needed to put the Bree farther out of reach due to depth of the controller, it might be a whole different story and I might care substantially more about replacing the knob action with controller wheel. Is CC mapping an option for you maybe?