I bought 2 these, one to drive my AmbiLighting with WLED and a remote instance of HyperHDR (Hyperion fork). It works great. I also printed the case for it so it looks great too. I am not sure if there is documentation for the pinouts (mapping ESP-8266 GPIO to the markings on the board) but I can't find it, and that would be helpful. I reached out to the maker and will update my review when I hear back. At any rate, I highly recommend this for any WLED project.
Update: I got a response from the maker. DI is GPIO2 and CLK is GPIO17.
Response from Shields and more | Jan. 17, 2022
Correction GPIO17 for ESP32 boards, For ESP8266 GPIO0.
Used this product for decorative indoor Christmas lights for family members. Product arrived just as described and works perfectly. The only thing that would be helpful is a little better documentation for the mini-shield version that tells you which pin is which, I eventually figured out which pin the clock output was connected to on the ESP32 but a simple document like the full shield would have been much nicer. OVerall, I will purchasses this product again if I need to create another string of lights!
Response from Shields and more | Nov. 19, 2021
Hello! Thank you for your review. Only one thing is I don't understand it's about documentation. Docs with connection guide is linked in description to this file https://github.com/srg74/WLED-wemos-shield/blob/master/resources/mini_shield/mini_connection_guide_v1.2.pdf . Best regards