@eaton I have a sociolinguistic jargon word at the tip of my tongue that I feel might be relevant in a US context: When learning a writing system requires learning a new standard variety or at the extreme, an L2. I remember examples from standard German (Switzerland) or Arabic.
Is a similar distance to L1-variety a factor (e.g. via AAV and Spanish) and potentially exacerbated through the English spelling conventions (re: ghoti / fish) a US idiosyncracy in literacy?