Well, that's what I thought your software did...

If it doesn't do a remap of the kits and megavoices, how does it even deal with the more minor differences between Ketron and Yamaha drum maps?

Things like EMC and the like, they have little look-up tables, so, when the style original says play Eb2 for a clap, and the destination arranger says play a Ab1 for a clap, the software changes it. You REALLY need this if you haven't already got it, then you create lookup tables for different products, and the same software can address a large variety of different destination keyboards and modules (this is also how you would remap for different Mega-voice layouts).

This is probably where you would apply any velocity curve and volume curve offsets, too.

Maybe this is a bit more complicated than your current program, but doing it enables you to sell the product to a MUCH wider market...

Most WS users don't HATE arrangers. They just mostly hate how dumbed down they are compared to the WS they have. If a piece of software allows them to use styles AND what is best about their WS, you bet your sweet *** they are going to buy it!