The existence of common slang which isn't used in the sort of formal writing that grammar linting tools are typically designed to promote is more of a weakness

The existence of common slang which isn't used in the sort of formal writing that grammar linting tools are typically designed to promote is more of a weakness of learning grammar by a weighted model of the internet vs formal grammatical rules than a strength. Not an insurmountable problem, ChatGPT will use "aight fam" only in context-sensitive ways and will remove it if you ask to rephrase to sound more like a professor, but RHLFing slang into predictable use is likely a bigger potential challenge than simply ensuring the word list of an open source program is sufficiently up to date to include slang whose etymology dates back to the noughties or nineties, if phrasing things in that particular vernacular is even a target for your grammar linting tool...