English is my primary language, so yes, I'm aware of the historical use of they/them as a non-gendered pronoun for hypothetical people.
I'm also aware of the fluid nature of language. I'm still salty about "literally" becoming its own antonym, but I have to accept it because it's now part of English.
That being said, it's never been socially acceptable to use they/them for a known person of a binary gender, and I'd argue that it's even less acceptable now, thanks to the common adoption of they/them as a personal pronoun for known persons of nonbinary gender.
It'd be much less confusing if there was an entirely new pronoun for enbies. Or, better yet, if there were never any gendered pronouns to begin with. But this is the world we live in, and we all have to find the best way to navigate our own paths without kicking up dirt onto others'.