I have just bought the iCasa 4-button Zigbee controller, available with 2/4/8 button, you can see it here: https://en.icasa.io/wandschakelaars
This is made by Sunricher and re-branded by several companies.
Unfortunately, ST has no native support and recognizes it as a thing. I have changed the device type to “Zigbee Button” and it works but only the top two buttons are recognized as a single button, the bottom ones are ignored.
I think that supporting these wall controllers would be great, they are cheap and integrate very well by replacing mechanical wall switches.
I have some basic programming experience, I may try to create a device handler, but I need some basic guidance.