I started looking at the isochronous streams stuff a few months back but it was hard going - there was a lot to learn and I couldn’t dedicate enough time to it to get anywhere useful.
Whoever takes this on, I recommend looking at maybe one of the BSD XHCI drivers to get an idea of how that implements the specifications above, and only when you feel you fully understand it, go for it. In my experience, it’s easy to get started on something and “run out of bricks” because it’s hard to see the full picture from the get-go.