As far I know there are several parts inside the Empulse with a know or leaked canbus protocol.
The best documented protocol is by far the Eltek charger protocol , this can give a lot of information about charging energy , pack total voltage , pack charging curve , cuolobic efficiency of the cells.
The motor controller is a Sevcon so everyboty able to "talk" with a Sevcon can read info from the controller , as noted above the canbus from Sevcon is NOT optoisolated from the traction battery , be AWARE that motor canbus GND is the same of TRACTION GND , one wrong connection and you can destroy the bike or get killed.
The not know protocol is the BMS , here only BRAMMO can help US