Unironically awesome. You can debate if it hurts the ability to contribute to a project, but folks should be allowed to express themselves in the language they choose & not be forced into ASCII or English. Where I live, English & Romantic languages are not the norm & there are few programmers since English is seen as a perquisite which is a massive loss for accessibility.
The hotter take: languages like APL, BQN, & Uiua had it right building on symbols (like we did in math class) for abstract ideas & operations inside the language, where you can choose to name the variables whatever makes sense to you & your audience.
I think they exclude some unicode characters from being use in identifiers. At least last I tried it wouldn't allow me to use an emoji as a variable name.
I thought the most mode sane and modern language use the unicode block identification to determine something can be used in valid identifier or not. Like all the 'numeric' unicode characters can't be at the beginning of identifier similar to how it can't have '3var'.
So once your programming language supports unicode, it automatically will support any unicode language that has those particular blocks.
Depends on the compiler, I'm pretty sure some versions of Borland shit themselves if you introduce an accent mark at the wrong time, much less support Unicode.