Struggled at first, fell asleep for about 5 hours, then made steady progress! Got 9d from the wordplay alone, but 8d was new to me and LOI even though I correctly guessed the meaning of issue. 20/26 was good and although 21a is a brand it made for a good anagram. I don’t think this is one of Paul’s best.
Brendan, I agree with your parsing of 20d btw, but not very satisfying. Still can’t quite parse 21a.