Kinesis Racelight 4S Disc Custom built

Sorry for the reply delay @hippy I've been riding a 1000 brevet https://www.strava.com/activities/635767414

I followed this guide, pretty simple https://theflyingarrow.wordpress.com/2014/06/05/getting-wired-sinewave-cycles-reactor-installation/ Forget that they are using another set of lights and usb charger, cables are cables.

Just peel both supernova and d1 cable ends, twist one of each together, then insert the two resulting cables back into the SP Dynamo connector

I didn't have the time/patience to seal the ends correctly... just abused some electrical tape and good to go (it doesn't rain in summer around here)

Supernova and D1 can work together , but light will have less power if D1 is draining watts. My improvement will be to add some kind of electrical switch to the D1 cable so I can cut it from draining power with a click, instead of fiddling with the unit to disconnect/connect the USB cable while climbing

I'm really sad that you can't finish your 4S Disc build :(, haven't had much time to read the forum, but as far as I know it was a problem with the rear wheel ? Not finding a suitable option with 32holes, centerlock and wide enough for 28mm tires? You have @CarlosBI now living in the UK, maybe he can help you with wheels (its his thing)