I think you'd be surprised how close it would actually be, seeing how German spelling is almost spot on to the written word.
Like here for example. I took the liberty to steal your post
Bii tö tseints juu vant to sii in tis völd." Du juu häv ä feivörit kvout?
"Be the change you want to see in this world" Do you have a favorite quote?
Good job on "quote" that's creative spelling. In "Vörld" the o in this case is actually an ö when looking at it with a German pronunciation.
Now, this is my attempt at that sentence:
"Bie dä tschänsch ju want to sie in dis wörld" Du ju hef ä fevorit quote?
I have not seen this kind of language, so I assume it's a new trend for English speaker. In the DACH region, writing like you speak your accent is a pretty common thing outside the major towns.
I'll leave you with a pretty complex example where the writer tried to show the pronunciation by using different circumflex to show how different letters are pronounced. https://pasteboard.co/rMJcvSHAFx6g.jpg
It's pretty extreme, but if you are fluent in any German alpine dialect you will have little problem reading it.