As the subject says.
I'm currently carrying two phones, a work iPhone and a personal S7 Edge. I'd really rather not have to carry the iPhone (I know, first-world-problems).
I've done some hunting around and can find dual SIM trays for the S7/S7E on sale overseas, but not sure if the NZ version of the S7 Edge accepts one of these. I don't want to 'just try it' in case I break something!
Both are Vodafone, if that counts for anything.