Thank you for sharing this @graycyn . We have an Android app that we just added support for EPUB 3 for reflowable and will be improving the EPUB 3 support for fixed layout.
https://play.google.com/store/apps/d...android.reader
We think our iOS app has pretty solid EPUB 3 support now but we might not have seen all use cases. Do you mind taking it for a spin with the a free account and sharing your feedback?
https://itunes.apple.com/us/app/bookfusion/id1141834096 . If possible could you share the sample EPUB 3 with us? Surely there cannot be too many good platforms and apps around that are interested in truly catering to readers.
We plan on working on accessible features around Q4 this year