nvidia only very recently opened up their drivers to open source dev, so the open source drivers available right now are still based on reverse engineering and they don’t work super great. there are proprietary drivers from nvidia but they are not easy to install and configure and popos handles that for you on install.
battery controllers and motor controllers are available as cheap, simple, stable, off-the-shelf dedicated hardware and there’s no reason budget evs would need to do any coding for them, maybe just some variable adjustment. those things are not controlled by the user facing software being talked about here.