I hate to post this in finished, since I’ll probably find something to improve, but at some point you have to say “it’s done”.
I’ve taken on board a lot of the critiques, both here and elsewhere, including showing to friends and their (non artist) comments. Had to cheat on shadows, and I have no idea why they were wrong (they shouldn’t have been, but clearly something wasn’t working). Nevertheless, the job got done.
Done with denoising and 750 samples. Could probably do with doubling to 1500 samples and denoising, but what the hell.