This one is probably for Tom, but everyone's opinion is welcome:
Firstly trumpet falls and doits - these are a great effect to have and they sound good, BUT in my opinion they are too quiet in comparison to the main note. I find that I have to increase the mod wheel at the end of a note with a doit or fall to hear the effect at an appropriate volume. Is this personal taste? or would an increase in the volume of these effects in the programming be an idea for a future update?
Secondly shakes - I understand how Tom has approached this subject, and a reasonable result can be obtained, but this requires a lot of micro-editing of midi data. I am approaching this from a playability point of view and would ask whether it is possible in the programming to have controls similar to those for vibrato - i.e. have a speed control and a width control, but instead of oscillating above and below the note, the effect would oscillate from the note upwards and then back to the note, also the width control would need to be wider than that for vibrato.
These are just uneducated/inexperienced suggestions - I am not criticising the JABB programming at all, just offering up user suggestions