Personally? I just open up the laptop and disconnect the keyboard header. Of course, this only works if you only ever use a USB keyboard with the laptop, but thought I’d add it as a valid method.

Seems like a silly solution but so just use evtest to disable the keyboard. Did a tiny bash script to disable and re-enable the keyboard by just tracking the pid

I used to do this on my touchscreen laptop, key combo to disable and 4 finger swipe to re-enable.

Wrote a small script that used xinput, ran the script as above.