Hey I'll have to look into that Bionx more it looks nifty! Blue back-light?
If the unit is programmable to some degree it will be possible to hook this up to a hall sensor from the GM controller, GND, probably throttle and power in parallel with the unit, very similar to the CA but I would say the CA is much easier to read in day or night condition in comparison.
The Bionx unless you can adjust the contrast will be hard to read, its the same as the motorcycle digital speedo I use that I am yet to get to function lol but it is difficult to read in sunny daylight
Anyways, I have a couple of e-Bike (scooter type) speedometers that accept a hall sensor, ground and lighting power. It has a pot on the rear to adjust the speed depending on the size wheel you are using. Analog speedo though... And chunky lol.... I too have been looking for something spiffy like this one!
As the speed signal (pulses) will vary between different wheel types/manufacturers is why I would expect this to be programmable to that extent. As for the PAS I'm not sure but it could be as simple as a signal wire and (hopefully) a setting on the unit.
If you have the internal MP (and are happy with your settings to last a long time!) then you could use the Yellow wire used for PC connectivity to send out your hall sensor signal. If you have the external controller then that just makes it easier...
Maybe if you can get a wiring diagram for the Bionx would be good to have a looksy