What kbrkr suggested is not really a free play style, although it might be an interesting non-traditional way to use your arranger. In a free play style, the bass is controlled by the automatic accompaniment engine, just as in a regular style.

Bachus I don't know why you keep insisting that Yamaha are doing something different, or have some kind of special programming. They do not. Did you ever LOOK at a free play style such as "Ethereal Movie" using one of the excellent 3rd party style editing programs which are available for Yamaha styles? Yamaha free play styles don't "follow your playing" any more so than any other style. They employ the same real-time chord recognition, which is the defining feature of all arrangers.

The main difference in a free play style is the absence of a well-defined rhythm (no drums or percussion, and long, sustained bass notes rather than a traditional "bass line.")

Depending on when you change chords, how many tones are in common between the old and new chord, and what instruments are playing, Yamaha free play styles may "glitch" just like a user style which is created using the same principles. If sync stop is enabled, a quick and clean transition from one chord to another helps, but the same would be true if you were playing full chords and bass pedals without accompaniment.

The trick is choosing instruments or voices which have a longish release and gradual attack. When you overlap these kinds of sustained tones on multiple tracks over several measures, and the keyboard has a well-implemented retrigger / repitch function (which Yamaha and Korg both have), the glitching is minimized and the effect is pretty convincing, if a bit dull.

I often play traditional worship music. No drums or percussion, and sometimes there are odd time signatures and changes in meter mid-song which are incompatible with traditional styles. Yamaha's free play styles are ideal for this type of music, but I have created similar styles for Korg and Roland which are just as suitable. No change in playing technique is required. Also for a different effect on the Yamahas, try enabling "sync stop", or setting a sync stop window.