I was able to spend a bit more time recently on the 5.x rewrite.
I have migrated off React to Preact as the underlying library. Preact is better suited for lots of independent widgets on the page.
I have also implemented the Single Select variant.
Both multi-select and single-select should be fairly ADA compliant using standard ARIA idioms and only a bit of custom announcing to the screen reader.
I have nuked the select2-react repo from github, and updated select2-5.x branch with the latest:
I am thinking we should make select2-5.x the default branch of the repo, and rename develop into select2-4.x to make it obvious that moving forward work will mostly be done in select2-5.x branch.
Thoughts on all of this?