Yamaha CS80

I've been looking for a note on/off solution for MIDIfying my CS50. Does anyone know if something like the Highly Liquid UMR2 would work? It says it needs a keyboard matrix to work.

UMR2: http://forum.highlyliquid.com/showthread.php?t=1133

CS50 manual: http://www.cem3374.com/docs/Manuals/Yamaha/CS-50_SM.PDF 

Thanks!