I don't know the solution, I'll be 100% honest that I saw 3 players doing the same thing and I decided to take the same betsize/bonus many of them had with MYR and signed up. Given the rules I figured its fair game for everyone, I wanted the same chance to win a prize.
I continued using MYR in the next comps because I was still wagering my 400% deposit bonus, my bets in the current comps are within 15% of NZD minbet so I'm not going out of my way in those active comps to play cheaper. The only other option is to double the bet which is paying ~70% over NZD minbet. I did PM coco about this asking if there was any issues with my bet size but it appears it went unread.