Maybe they’re known in US, but I never seen them in EU.

Then you didn’t look properly: https://geizhals.de/8bitdo-ultimate-2c-wireless-controller-pc-android-v177372.html Gulikit is another very famous 3rd party controller brand. I think both source their sensors from the same manufacturer. They often have quite similar controllers.

Reverse engineered xone driver for dongle fails every few kernel updates.

So the dongle is the problem, not the controller. Use a USB cable for best latency. Works fine. Literally every other controller doesn’t have this problem, so specifically needing a Steam Controller because of Linux compatibility is nonsensical.

So if you want one with a dongle that works absolutely fine under Linux and costs only 29 Euro: