I’d like to share another finding I made as the stability seems to be directly linked to the power demand/supply:
- with ESP32 (instead of Teensy) I still got the occasional wrong colors, followed by I2C crashes
- I’ve then cut the 3.3V power supply as mentioned in the hookup guide and connected the LED strip to an external power source via VIN (power comes from PoE Micromod Board).
- With that external power supply, all stability issues are gone. The strip works perfect, even with rapid changes in color and brightness.
So maybe the muxer and/or clock stretching isn’t necessary / the reason after all. But I keep it for a completely separate reason.