Set keyboard illumination to specific value

I see that BTT has an action for setting the screen to a specific brightness, but not the keyboard backlight. Would it be possible to add that?

I am specifically interested in being able to set the keyboard brightness to a much lower value than the standard step size.

(It would also suffice to be able to use “small steps” like you can with volume and screen brightness, but again I don’t know if this is possible for keyboard illumination.)