Josef Bacik who was working on this said:

I fixed up all your review comments, but yes we don’t care about this internally anymore so it’s been de-prioritized. I have to rebase onto the new stuff, re-run tests, fix any bugs that may have creeped in, but the current code addressed all of your comments. Once I get time to get back to this you’ll have a new version in your inbox, but that may be some time.

(Note: This was back in April.)