Spyware:
I thought the Voda Huawei's had the firmware cooked to not allow PPPoE selection.
Nothing stopping you from flashing stock HG659 firmware, but I logged into my bench's HG659 (I have all 3 Voda CPEs in the last 8 years) on B026 firmware and just changed the WAN to PPPoE without any fuss.
I am using the slightly higher admin privileges however which can be achieved by using Admin/@last8digitsofserialnumber
Unsure if this can be done on the bog standard vodafone user(I would recommend using the Admin one anyway for more access)
Unsure what PPPoE performance is like on this HG659 however, would be interesting to see ;)