This is one of the three units I made so far:
Note: I assembled the resistors/pin headers for only two button inputs, because this is that WLED supports (AFAIK).
I changed the series resistors for the two inputs from 1k to 470R because that worked more reliable in my case.
And I had no 100n as THT in stack so I just used a 0805 and a small piece of wire.
Thanks again, works perfectly! 