It would be nice if there was a possibility to add a phonetic name to streets/cities where the TTS clearly pronounces it wrong and then for the client to read it out if it exists.

Everytime I get directions onto Watling Street it pronounces it Wahtling rather than Whatling (I would do it in IPA but I don't know if the forum will render it correctly!)

As a further example in Milton Keynes there are these three districts - Loughton, Broughton and Woughton [on the Green] - the first ou is pronounced as in loud, in the second it's pronounced as in raw, and in the third it's pronounced as in wuff...