Can find a short overview of it here: https://www.privateinternetaccess.com/blog/2018/08/beyond-th...
Yes, please.
As it stands today, it's too much work to set site-specific cookie privileges.
The problem is that it's not a technical problem, but a political. No matter how technically elegant your spec, it doesn't change anything about the underlying conflict of interest: Website operators want to collect personal data and show ads, while users want to keep personal data to themselves and don't want to see ads.
So trying to solve this via any kind of web standard is asking the website operators to act against their own interests. If you have no enforcement or incentive, you will end up with a standard that is either toothless (P3P, DNT with opt-in) or simply ignored (DNT with opt-out).
GDPR (and the cookie law before) do have enforcement, which is why web sites can't ignore them - instead they fight back with a barrage of popups.
Honestly though I think it's sites being dumb and storing the choice in a session cookie or something because you've not agreed to storing cookies
Hell, if you've got a marketing team dependent on stuff like Google Tag Manager, then have them throw it in there. Job done. Not great for the users.