I'd be suprised if they'll touch it tbh. Ive not heard of anyone building a pedal for those can bus type systems. Could be wrong but it's a frequent question that I've not seen resolved.......Yet!Try SMP Stourport On Severn, they are the best people I have found for footpedals, and may be able to help with a less expensive option........................
Surely someone will make an aftermarket version at some point!