I do the hang test by the neck, not sure how scientific it is, but the first 6 silkies we bought we were 100% on the sex, can't wait to see if I'm right with this batch. I did do the wing test which confirmed what I think they are, but I've heard it isn't accurate with silkies.
I'm a little late to the thread, but I set my first batch in December and 7 of 8 in lockdown hatched between Jan 2-4. They are silkies so tiny and adorable. Not at all as loud as my Australorp chicks when I brought them home last year!