After a few months with this fix, I do still prefer invert when heavy text reading. If you turn on both invert and 'zoom', you'll get a list when triple clicking and can go back and forth. Just don't use both together
Just wish apple would implement true flux. They are eager to improve health outcomes and their own devices are disturbing circadian rhythms (which itself encourages inflammation) the world over!
As far as shortcut to it, or at last close to it, you can likely use an app like Launcher and create one that you can access through its widget in the notification center.