i am on stable one ui 2 and i can confirm force dark mode doesn't work on both of them. The only way i know right now that we can have both of them in dark mode is through some custom theme application like hex As for digital well being u can just go to the app details and remove all the permissions given to it. Also clear the cache as well. That should do it.
It can be... i had done it on android pie. Please see the steps i have mentioned above. Disabling it does wonders for the battery. In my android 10 I have not accepted the terms when I open it. So it won't work unless i set it up.