Yes I know, but there's no in-band way to say "this file conforms to the schema in this other file" like you can with XML or JSON schemas.

For Cue you would probably just want to #include a file... but as far as I know you can't do that.

That makes it far less useful for IDEs, linters and so on.

I don't think there's any reason they couldn't add that feature. Just a bit odd that they haven't already.