Just would like to share my experience when applying for smc resident visa. When we submitted our EOI, my partner had been studying and I working in different cities for several months. Though our relationship started more than a year before we moved to NZ, we were really worried about what this would do to our application.
After we submitted our ITA, our CO asked about our living arrangement as they had our then-current visas as a student and a worker in different cities. Fortunately for us was the fact that these cities are within driving distance, so I always drive to where she lived at the time during the weekends and holidays. She would also visit me at times.
Based on this, I submitted a printout of my driving history over 10 months where I drove up every friday and back every sunday. This is possible through google maps as it tracked your every movement if you allows it, complete with timestamps and all. We also asked our respective landlords for a support letter as further proofs that they had seen us visit each other.
After these were submitted, there were no further questions from the CO so he/she must be satisfied that our relationship has substance even though it might not fulfil the criteria of 100% physically living together.