This might still be a difference, I haven't changed the sysctl on my end (although I didn't see any difference between the default 3 and 12, which is why I just left it as-is).the log makes no sense because with a mask set to 12 i don't see why Xorg is attaching the keyboard multiplexer via edev in the first place. I thought the point of the mask was it would only use the hardware for edev.
What I get on my end:my keyboard is mapped as a pc105
Code:
> setxkbmap -query
rules: evdev
model: pc105
layout: be
options: terminate:ctrl_alt_bksp