This preset is achieved by using apple's private framework CoreBrightness in AppleScript-ObjC, for the one who's only interested in the code, refer to the source folder in my repo: https://github.com/noonchen/BTT_NightShiftSlider, I'm hoping my preset can give you guys some ideas to create amazing presets/widgets.
Edit: I underestimated my ability to suss out the the problem. I opened up the scripted action, and changed the ns(.5) to ns(.9) and it works now. Excellent to include the slider!
When I use this, toggling it on it always defaults to the center color temperature of 4100 K. Is there a way to edit that? I have my system set to enable night shift much warmer than that, but it doesn't work with this as a trigger.
Thanks for your feedback! I'm thinking about storing the strength to a BTT variable when toggling it off, so that we don't have to adjust the slider everytime we turn it on.
I really want to use this but having the same issue and an additional one: even though I disabled schedules on macOS's settings, after a while sometimes temperature will randomly reset back to normal, which is quite annoying. Thanks!