Parkrun done and head cleared. I had answers for many but couldn't parse before but I've worked through it now. 22a still not parsed and the penultimate letter replacement in 5d I don't see how you get it.
FOI 9a. LOI 16d (not my favourite clue). COD 6d. For the groan factor.
Thanks Kite. Turned into a tougher challenge than I thought it was going to be.