async Yes, I use a low level API for that. There are actually several APIs to manage Presets, including a high level one that Apple made for System Settings - it's a bit clumsy but otherwise works fine. If you are interested, I can send you the details, but you'll need to do heavy coding to utilize it.
FNP7 Thank you! Many of the techniques should work on iOS/iPadOS as well, but did not experiment with it.
Donux Yes, you can use terminal commands. Download betterdisplaycli or just use the binary inside the app bundle. Example:
betterdisplaycli set -n=displayname -quantization=0.5
Here is more help: https://github.com/waydabber/BetterDisplay/wiki/Integration-features,-CLI
async I was planning to add some shader effects to BetterDisplay. Right now if Metal overlays are enabled in the app (a bit difficult to make that happen now as you need to change some awkward settings) you can do some simple color adjustments with it only (temperature, RGB control etc) - I primarily added this to support a night shift like effect on non-native displays (on which gamma table adjustments don't work) but did not expand the featureset much. So much to do…