Travelling to NZ on visa-waiver while WHV Transfer is pending

A little background: I received the Working Holiday Visa last year in December, but renewed my passport in January and forgot all about it until earlier this week. I rushed to submit a visa transfer application 3 days ago and since INZ said that the transfer generally takes 11-20 days, I included a cover letter explaining the situation with my air tickets.

I am flying in 3 days and there has been no news. I am from a Visa-waiver country and therefore shouldn't have problems going into NZ without a visa, but I am worried about the Visa being cancelled because I am on NZ soil, or because Visa-waiver counts as a visa or something.

My question is, should I come clean at the Customs with an immigration officer or just go through the e-gate under visa-waiver? I am worried about being denied entry if I come clean, but I do have my old passport and emails stating that my work will only begin on 20th March (more than enough time for transfer to be done). I will only be sightseeing for the first 2 weeks. Advice would be greatly appreciated.