A roaming eSIM would work the same way as a roaming SIM. Just because it's easier to set up (no need to get a physical SIM) doesn't change the regulations around it.
I believe some travel eSIMs are actually issued from outside the country you're going to.
And as you said, ones marketed as "China travel SIMs" are typically issued from Hong Kong. Interestingly, Hong Kong also has an ID rule (though it allows self upload of ID anyway), but it exempts these roaming-only cards. If you want the card to work in HK, and it is issued from there, you must scan your passport to activate it.