"Another restriction of this design is that fills will always complete a full bar, whether you like it or not. You can't trigger a fill part way through a bar so that only the last bit of the fill sounds. You might wish to do this just to add a small accent towards the end of a bar, rather than triggering a full blown fill lasting the whole bar long (there is a "half-bar" facility on the instrument, but this is not the same thing at all)."

Yes that is a big problem......