I've been away from SZ for a while and just saw this post.

Bachus is mistaken. Free play styles do not follow the player's tempo, and really do not require special programming. They DO require that the arranger have a "retrigger" functionality as a style parameter, a playback parameter, or programmed into the voice characteristics.

Both Yamaha and Korg have Retrigger available as a style parameter, so creating a faithful approximation of Yamaha's free play styles is eminently possible on a Korg.

Please search my posts here and on korgforums.com to find and download a very simple free play style for use on Korg.