For the record, I've been working on something like this: https://observablehq.com/@jobleonard/circular-buffers

The main thing preventing me from publishing is that @mootari pointed out that with a little work I can make it match the normal Array API almost completely (I don't remember right now where I differ) and I haven't gotten around to fixing that

Also I think I should add your bit vector implementation to that set of "typed dequeues"

👍