I'm confused... If you have to LOOK at the Audya to do scrolling, and style selection, etc., then it's GOT to be close enough that you could actually scroll on the unit itself, surely?
BTW, the button presses are single value variables... Just imagine that, if you moved a slider, for each new value that the slider hits (all 127 of them if the resolution is good enough), the remote has to send out the entire sys-ex string, again and again...
Plus, of course, the actual PLAYING data gets delayed, shifted around and held up while the entire sys-ex package gets sent. You'll find it very rare that a slider's output (or knob, etc.) gets sent in sys-ex, for good reason.
I used to create mixer templates in Cubase for sending out sys-ex, and editing Sound Canvases, etc., and I ALWAYS had problems with the timing if I sent a string of data values in sys-ex (say a chorus rate parameter, or something like that) while the sequence was playing.
I STILL think that there is sufficient demand for the arranger manufacturers to get together and standardize the MIDI codes for controlling the arranger sections in different arrangers. Think how simple it would be if, when you press the button for Variation 2 on arranger A, it sent out a code that arranger B would understand and do the same thing...
No more arguing about which SINGLE arranger is the 'best'... you simply buy two or more of them, and MIDI them together and they play as one large über-arranger. The strengths of each cover up the weaknesses of the other.
Wouldn't THAT be nice?