my take on seller's warrenty is even if the importer seller still exist, their job is to send it back to china on your behalf, during the period that the seller indicated and provided they honor the shop warrenty, and not servicing the phone like actual Oppo does. This back and fro from china could take a couple of months, and if its your main phone u have to be willing to wait that long also. So my usual rule of thumb for import phone is i'd just take it that the phone has no warrenty. But of course if the buyer travel to china often themselves they could send it in themselves.
Also, personal experience with the international warrenty is that when my sister's N2 flip internal LCD got a black blob for no reason, she just assume that there wasnt warrenty and wanted to send to CN service center through her china BF, and the service center did not wanna take in the phone for repair, even though there is international warrenty and that she said she was willing to pay for the replacement screen. End up it was brought back to SG and i brought in the phone to the local Oppo svc ctr and it was done in 2 hours instead, for free.
