This idea gets a +1 from me. I always wanted to display a mixture of keys and custom note names at the same time. This would be very helpful for midi instruments with keyswitched articulations like eg orchestral samplesets or RealStrat.
It could look something about like this:
I added the kontakt-style color overlays because i´d loooove to have them but the idea works without them too of course.
For mapped drums I´d prefer the "named view" look, though. It would have to be fairly tweaked over time to make routings to other instruments and channels possible, and allow muting of individual notes. But moving of note lanes would indeed be a great starter into the right direction.
That all said I am happy about any improvement to the midi side and generally exited to see what the trio comes up with. I am new to this and can tell you it is a thrilling experience to watch Reaper grow.
Frank