I wanted to use my Anne Pro 2 mechanical keyboard instead of the built-in laptop keyboard by placing it on top of it so it doesn't occupy extra space. The problem with this setup is obviously that some keys would be pressed accidentally…
You can block the internal keyboard - as internet suggested - by disabling or if it's not available, removing the device in Windows Device Manager. I didn't like this solution at all, so I prevented the unintended key presses physically, using 2 skewers which I cut to the desired length and placed between rows to lift up the mechanical keyboard.
Since this design was very slippery I wrapped the skewers with thin PTFE thread seal tape and the keyboard doesn't slide-slip anymore and is now sitting quite stable on the skewers.