I don't think I'm particularly doing this Malkovich thing very well. I keep cutting my comments a bit short in favour of getting my move played sooner.
What I meant about black resisting instead of backing off at 16-18 was the following read:
B17-19, w16-18, b19-19, w15-18, b14-17, w14-18, b13-17, w13-18, b12-18, w16-19, b15-17, w18-18, b18-19, w19-15.
However I'm not sure I can't cut through and do better.
If black does back off then I have to work out if this corner is large enough for me to capture the ko. There are ways to work out a ballpark value of a move in a step ko situation like this but I'm quite sceptical of these methods and I think they break down a little bit when the balance of threats is uneven like this. Moves around the centre left are not small