>I used to do NYT crosswords with my American partner (I'm British) and the wordplay never made sense to me
Can't say I've ever tried an American cryptic [I regularly do the UK Guardian and Telegraph ones] but the ones quoted above don't make sense to me either:
>Q: “It may turn into another story” A: Spiral Staircase.
Would be "...turn into another storey". In a UK cryptic there'd have to be an indication that there was a homonym involved story/storey.
>"Pasta dish at the centre of a murder mystery...The answer was poisoned penne.
Ditto. UK version would need to indicate a homonym was involved pen/penne. And, as someone else points out, a 'Poisoned Pen' is a letter, not a murder mystery. Very strange clues indeed.
Some freely available UK cryptics:
* Guardian Quiptic: https://www.theguardian.com/crosswords/series/quiptic/latest
* Guardian Everyman: https://www.theguardian.com/crosswords/series/everyman
* Chambers: https://chambers.co.uk/puzzles/cryptic-crosswords/
RANDOM ASIDE: My favourite anagram, which has been involved a couple of times in UK cryptic clues is:
VINDALOO AND RICE which is an anagram of LEONARDO DA VINCI