My preference is to immediately remove cookies from domains, as soon as (or just some seconds after) a tab with that domain is closed. Except some whitelisted domains specified by me.

To do this, I've used – for years – Cookie Autodelete. But I've discovered now that it doesn't work with Firefox's Strict Mode (the extension says "strict mode is not supported").

All in all I think my understanding of Firefox's capabilities and policies regarding cookies and similar extensions is outdated. I'd be grateful to anyone who can offer insights or links to well-informed sites about this.