Is it possible to link to highlights on the Kindle app now?

This new update from iDoRecall suggests it is, although there appears to be a bug.

Looking at that quickly, it seems to me that the link information is garnered from highlights that have been exported from Kindle, rather than from within the Kindle app. Can you paste a couple of links here so we can see their form? If they are well formed URLs, then once you have one in your clipboard, you should be able to use Hook with it.