> 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.

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?