Finished, sooner than usual and before reading this thread ... though I used Crossword Solver on, I think, 3 words.
FOI 11: leapt off the page with "Kant" and "criticised", though I don't know why I know that title
LOI: 1d, which confirmed my tentative12a. Used Crossword Solver with crossers from 8, 10, 16 and saw the light.
COD: yes, me too: 23a (and had jotted that down before reading the thread).
Took a while to get started beyond 11 and 5, but then made steady progress.