I got it working in the end. That tobias dude emailed me directly, great guy. The v4 does not require any initialisation, so act as if it's already initialised. From memory as the bike is on, put it into turbo mode, then up up down down up up and it displays 45. Works great.
I've got a Bosch gen4 with smartphone hub - according to this pdf and this video, it should be compatible
But here is me trying it today, instead of the expected 11kmh, I get 00kmh which means it didn't activate.
Anyone have any experience with getting the volspeed to work with the smartphone hub?