Perhaps they could take the lead, rather than just play catchup...

A dedicated fill for EACH and every transition. 16, including Fill-to-same. That way, you guarantee no glitchy transitions. And, to be honest, it makes the style easier to program, not harder. The most difficult thing to do in style creation is designing fills that work for multiple source/destinations. As witness by how many of Korg's styles suffer from just the two fills. Creating a fill that only has to come from ONE place, and only go to ONE place is a piece of cake...

It's only data. I see no reason why, if Korg are willing to address the fill issue at all (which they haven't in the past), why making a 16 fill arranger (or twelve, if you skip Fill-to-same) would be any harder than simply stepping up to six... Might as well leapfrog the competition while you are at it.