Many thanks for looking into this, Kevin.
Based on what I have seen with the images I regularly encounter, seeing alt-text entries in image metadata is very unusual.
I work with a small non-profit publisher, creating epub versions of their print books and the books often have images. But this is the first time I have ever seen images that contain alt-text entries in their metadata.
It was nice not having to write alt-text , but it was also not at all difficult to copy and paste the alt-text using the very user-friendly alt text feature in Access-Aide.
So I do not think that we need to proceed with this feature.
Another reason not to do anything relating to alt-text in image metadata is that some of the alt-text entries that I saw more properly belonged in an extended description.
See:
https://kb.daisy.org/publishing/docs....html#extended
So much of what is actually needed for accessibility depends on the context in which the image is used. So the alt-text in an image metadata might not be suitable for every context in which the image is used. So it's probably better to work directly with each image to provide the best alt-text in the circumstances.
Thanks again, for looking into this, it was very helpful because it prompted a deeper dive into this entire topic.
Jim