Very good as always from Kea. Very happy to have got to the full 12 evenings.
2 loose ends for me. 3a I'm guessing the word play is 6,2,2 (?), but the 6 doesn't appear to be in Chambers and the 2,2 doesn't mean what it would need to as far as I can see?
8d I don't understand what Sylvan/jumper is doing - seems like the clue would work without that there?