Floundering somewhat here. I presume 1a is one of the "treated" answers as I have TAURUS and the clue reads "guess author is unhappy removing front cover of Oxford dictionary". Help with parsing this might set me off again, if anyone is willing to help.
It's not Taurus, it's one of the treated answers as you say but with what's left of a longer word (def. "dictionary") after removal of one of the thematic words.
I'm struggling to find the last special light - is it 8D? I have four synonyms in one group and the same word three times in the other. The entity to be removed, and the puzzle itself are great, but the last bit of sardine in the tin is tricky.
Nor me, and it seemed a tame ending to a quite challenging puzzle.
Earlier on when I had a vague idea of the theme I was expecting something like an outline of the glider built in Colditz - or maybe a wooden horse. Maybe 'entity' was just a tease.