Great write-up. I obtained some samples of 5V seed pixels from Ray with 5cm and 2.5cm spacing and the 15 cm spacing DC5V 500ct/string WS2811 LED 16.8mm milky white 3d string light. The latter showed up best when laid out on a lawn.
The sequence is from Magical Light Shows (Tom BetGeorge) and remapped to my display. I really like Tom's arrangements. I also get the majority from PPD (Pixel Pro Displays).