@rrruuuqyou I was going to suggest you just use Forget me when I close this site and have it enabled by default. Then when you visit websites like Yahoo where you want it to keep your data, you would turn it off via the Shields lion flyover.
So I would go to Settings → Shields and enable it like below.
Global Setting:
This basically is combining the other two steps into one. It allows cookies just long enough to do what you’re needing, but then when you leave the website it purges the data.
The whitelist would be disabling like I mentioned. So for example:
So in the above, that’s the “site specific setting” which is seen by the Shields lion icon. You see there’s the forget me when I close this site toggle. It’s on because I had set the global one to on. If I turn off the toggle there, then it will whitelist the site I’m at. This means it won’t clear the data when I leave the site like it would otherwise.
-note-
Overall I guess you need to pick one or the other. Either the built-in Chromium method as you first were experimenting, or you rely more on Brave’s built-in options and privacy controls.
Trying to modify both will likely result in headaches. I did want to present this option though as it should work better overall.
Sorry if I rambled a bit or perhaps didn’t phrase things quite right. I should have been in bed hours ago but didn’t quite make it there. So I’m replying here as I’m kind of “running on fumes.”