I finished my 16th airline on November 29th. 7 airlines were on award flights. 6 revenue flights credited automatically. UX retroclaimed easily later.
I used the retro form to open a manual claim for CI (China Airlines) on December 7th. Still not heard back. Issue was China Airlines website didn't allow 2 first names, so I only gave them my 1st firstname.
As everybody else, VN is not possible to retro-claim, so I contacted customer support chat on Dec 10. Customer rep could see my flight, and told me it would be sent to back office and points would be given within a week. I didn't get a case number, and haven't received any points yet for this either.
So I am officially still at 14 registered flights with 2 still missing. I think patience right now is a virtue.