Look, I’ve been speaking English for work and pleasure for thirty years now and I’m here to tell everybody that prepositions in English are arbitrary conventions and it’s all mostly fair game.
Unless you are trying to precisely identify the position of an object relative to something else, the “correct” preposition is a few years of consensus away from changing.
I am viscerally against this concept.
It’s one thing to include the spelling as a way to capture the phonetics of an accent or a dialect, entirely another to accept its use in writing when using a neutral voice.
If anything, because it’s so often just a misspelling I would avoid trying to use it as a phonetics thing just as a matter of style. At this point everybody would think I’m making a mistake instead of trying to mimic a way of speech in a way they’d never do with “coulda”.