Re Custom filter lists
https://adguard.info/en/blog/review-issues-in-chrome-web-sto...
https://adguard.info/en/blog/review-issues-in-chrome-web-sto...
They did say they'll get the issue resolved in time. I use another extension that requires a filter list or things start to go haywire. I'd probably give up that problematic extension before going back to Firefox.
Reading that, I am still sticking with Adguard over uBO because it does sound like they are at least trying to implement these things. uBO is just pointing people towards FF.