[RedShift1]

I can't say how it is for the Thinkpad but most of the time keyboard backlight control is done in hardware. You can catch the keypress event and sometimes control it from the OS but the dimming/brightening works completely independent of the OS.

[t-3]

Yeah, kb backlight even works under Linux most of the time. Monitor backlight works everywhere out of the box under OpenBSD though, nothing at all like the hackish mess on other systems.

[oynqr]

Except when it doesn't, like on T450s laptops for instance.