Ask HN: How is international (Unicode) email address support in 2022?

Playing with IDN domain names, I had several problems with services supporting such email address:

- Gmail doesn't allow me reply to a friend's email, though they could send to me - GitHub would 500 out when adding a GPG key with a UID with Unicode email address - Some services can't outright send the email to such an address

A thread from 2017 https://news.ycombinator.com/item?id=14831756 and one from 2019 https://news.ycombinator.com/item?id=19013617 showed that the support was poor. I wonder how it is in 2022?