Without knowing much about drums yet, I only presume that the choke function actually sends a midi signal over the jacks that short circuit the tip with the sleeve, or sends a 'volume 0' signal to the brains.
I think if that would be the case, aftertouch will be impossible, as you would want to send an analog signal over a digital 1/0 connection.
I could be wrong here though.
What IS possible, is if Alesis would build a small program (update firmware), that will allow you to set the intensity of the choke.
In some video's of alesis I saw the choke nearly instantly muted the cymbal, which is not really very realistic. On the Roland kits I tried, the choke took too long to realistically be muted.
Alesis needs to create a curve that when cymbals are choked on a low volume note they nearly instantly mute, while when playing very loud, the choke should take longer.
and apart from that, inside the software, create a possibility to set choke shorter or longer, and save that as a preset (or drumset).
That'd be my opinion about it, but like said I know nearly nothing about electronic drums yet.