It occurs to me that in an alternate universe, the answer could be "both spellings are correct", because logically speaking, if both pronunciations are correct, shouldn't the same apply to the written version?
Come to think of it, the idea that a word with many correct pronunciations has only one correct spelling is actually totally weird! Why should writing be more prescriptive than speech?
That is not a requirement for updating the orthography or even the spelling. It also wasn't a requirement for introducing the writing system, print, etc. I doubt English has ever been pronounced the same way everywhere and likewise for any other language. Regional differences in spoken language did not stop e.g. Germany from updating its textual representation.
Funnily enough, your example looks perfectly readable to me. I'd guess it would be about as hard to read for English native speakers as Dutch is. It needs a few fixes (rivized -- only the first one should be an i, etc), but something like that would definitely be an improvement over current spelling.
Which pronunciation will you choose? If you are a prescriptive linguist from Newcastle you will presumably expect everyone to use a short a in 'castle' but someone from the south would use a long a. And which language do you have in mind when you imply that there are languages that are pronounced in the same way by all of its speakers?
Anyway, there is no Academy in charge of English so if you want to get started on spelling reform just go to it. Promote your revised spelling amongst your friends and colleagues. Or should that be: 'Promoat yor rivized speling amongst yor frends and koleegs.'?