I’ve used some WS2801 LEDs for notification on my Magicmirror build. Unfortunately with the update to Raspbian stretch they were no longer working with the MMM-Pilights module which used the rpi-ws2801 node module.
I was able to find the reason for the no longer working SPI LEDs in the raspberry pi forum where bulletmark was facing the same problem. With the change of the default SPI frequency in the raspberry pi kernel the rpi-ws2801 package is using the wrong frequency for SPI.
I was able to modify the node rpi-ws2801 module and set the default frequency for the WS2801 LEDs to 10MHz. The result is in my fork of the node module: https://github.com/Trekky12/node-rpi-ws2801