Thanks to Picaroon for this week's Prize challenge.
I found this difficult, lacking the GK to quickly see the theme (no spoiler; clearly a themed puzzle), which only slowly became apparent. But great fun, with much ingenious and complex wordplay. And the theme was much less obscure (to me) than last week's ordeal. 🤣
FOI 16, not much success on first pass. Needed some short words to get a toehold. Didn't notice any straightforward anagrams.
No single COD: 12, 20 and 23 share the podium with 13, 15, 17, 25 and 27 also getting consideration.
LOI the grid was 21, but full parsing of 4 and the theme-defining (9,3) required considerable additional thought.
The grid is amenable to Ninas, but I didn't see any. A few solutions hinted at a pangram, but that didn't materialize either.