Is there a better way or a trick to find tags, I have added/removed, which have been removed/added afterwards, by someone else?
Something that's easier than going through thousands of tag changes?
I know I can search for tags, but then there are still dozens of pages for me.
And I have tried searching for: Final Tags: solo_focus, Removed Tags: solo_focus, on my post changes page, but that's not how it works, as I have found out.

Sadly, username; added tags is the only search you can use, and just have to look for struckout versions of that green tag. In the linked example, you can see that nine days ago I added on Spanish_text and translation_request but the request was removed.