Brendan, the first four letters, with the final one ignored, are the same as the word given by the word in 31d with the extra letter in it with the term for level and an R inserted (i.e. 3 + r + 4)
This was a tough solve with many optional misdirections but it revealed itself slowly through guesswork and back filling.
I also spent a while looking at a possible 8-letter name running from 2nd row of 6 down!
I don’t know if it’s a red herring, or the puzzle changed in its evolution, but one of the 7 letter thematic’s sparring partners largely appears around the SW perimeter. And changing the final letters to give the surname even leaves real words. Quite a coincidence if that’s all it is
Grid 80% full. Still not seeing why some answers are not entered fully.
Help with straight clue please. 21d. Appropriate Macbeth’s pain’s endless, master part. (7) I have ?RE????
Lumen, the not entered fully answers are entered fully in one sense - have a look where two of them intersect. It's something that occasionally occurs in themed crosswords.