Some of it was my bad. I had missed the call to `main()` from my python script.
Then microbit spi modes aren't as documented.
Trying other modes i get a valid response, but it's not glitch free. Especially when blanking all pixels
Neopixel RGBW
Re: Neopixel RGBW
If you look at the data stream with a logic analyzer you will most likely see that there are gaps between the bytes. Once a gap is longer than ~60µs, it will be considered as a reset of the LED.