It's already in the commitfest, although I think it's almost certain to be pushed out to the September CF. I'll add this email to the existing item.
Thanks Andrew; I was gonna do that once the email gets archives but thanks for taking care of it. I changed the status to Needs Review, though I understand this patch might be pushed to Sep CF. There were suggestions in the last release cycle that this feature should get early into PG12, if at all, given the complexity of the patch. So I thought it makes sense to submit it early.