I gave up on the Vax Cert and went to the Bureau of Quarantine in Bacolod yesterday to get my International Certificate of Vaccination. Appointments, documents and payment (around P300) can be made online @ https://icv.boq.ph
Take your vaccine card/cert and passport/ID with you. It took me less than 5 minutes to get the certificate once there. The BoQ is located at the main ferry terminal on the second floor in Bacolod.
The road to Bacolod on the Mabinay route is ok up until Mabinay, decent enough until Bago, and spectacular after that. It took me around 4 to 4.5 hours by car. On the way before Kabankalan they had a checkpoint checking for vaccine cards, no other restrictions at this time. I was not stopped for anything on the way back to Dumaguete.