> I think I need more Zigbee repeaters to get a reliable mesh network, but to date I haven’t found any consumer-grade devices certified for use in NZ.
Since many devices are also Zigbee router (it's a mesh network after all), maybe some additional lightbulb for exterior would suffice ?
Pretty much all mains powered Zigbee devices also act as routers in the mesh.
This - the move is to grab some zigbee smart plugs. Once you have HA up and running there are so many applications for these.
I have a door sensor that monitors my kids bedroom door, and when it opens it turns on a desk lamp in my room. This allows me to get to him before he gets to my partner who's sleeping with the new born.