I have the same for 2 months now and I just ignore it I sent all my additional docs thru VAC in Makati but 2 weeks after, I also sent via email as granted by the guy who called me from the embassy
Makes me feel better knowing we're not the only one with the "optional" request.
Thanks.
I see you files back in December. Hopefully you get your VOH soon.
I saw a couple of March applicants already have PPR