re: using midi-in to access preset voices
Although I am not exactly sure how it is accomplished best - the fact that midi accordions are used in conjunction with Ketron products should make it obvious that midi-in accesses the best (preset) voices on the SD1. I have tried playing the SD from my Roland FP3 because I am used to acoustic piano action - it took me a bit to find out how to access those sounds - but it was definitely doable - and I will try to recreate it. Surely internal midi-file recording through the sequencer or song record functions allows one to access the preset voices - so it isn't likely that access will be denied from controller keyboards or remote sequencer.
Just a side note here - not completely related - I believe that physical access to the most important parameters of the SD1 is fully functional. - One place they can upgrade and benefit the most I believe is enabling seamless and simultaneous tempo/beat coordinated interplay between midi-files (as songs or song parts) and live arranger play. This sort of integration might do wonders for the arranger keyboard - keeping a standard rhythm section w/ variations for a tune - and then bringing in a pre-recorded backing at will - something that could be re-done at anytime without having to redo the whole tune. Oh well - that's where my head is at.
BTW - I think the SD1 is nothing short of phenomenal - and with tons of upside potential in OS changes
Mike H