Having a C or Cpp based driver that works with Sevcon controllers out of the box, without having to configure/program those Sevcons, due to costs and complixities involved as mentioned in this thread a few times, is the best possible solution for me.
Python & Node-RED might work as well and offer lower barrier wrt people modifying it. But cone at CPU cost,
Wrt Node-RED: the next step for anyone is to simply try it. Few hours work max I’d think.
Before going into Node-RED, make sure that there is data coming in, run candump from the commandline. See google for candump details.