[REQ] Two stage behavior

[Gouster4]

Hello. I like this extension.
But i guess its feature to use screen dimming and backlight control isnt ideal.
Currently it does use whole slider to set both values.
My idea is to set backlight brightness in first stage (50% - 100% range), and dimming in 2nd stage (0% - 50%). (as optional feature)
0% - minimum backlight value, screeen dimmed by sw
50% - minimum backlight value, screen not dimmed by sw
100% - maximum backlight value, screen not dimmed.
50% can be configurable to any percentage needed.
im using this extension to lower my minimal possible screen brightnes, but now it seems that when i dont set brighness to 0%, i have bright backlight even its dimmed.

Thanx.