Only small selection of smart home switches are AUS/NZ certified. Most of the products use Tuya platform. Only small set of switches use Espressif ESP chipset. Tasmota firmware can only be used in Espressif ESP chipset. In this article I will list all the smart switches that can be legally converted to Tasmota without voiding AUS/NZ certification.
1. SmartSetup Homekit Certified WiFi switches
StartSetup generic branded HomeKit certified 1/2/3/4 gang switches are AUS/NZ certified. I was surprised when I open the device using Espressif ESP32 processor. All header pins are populated for flashing for open source firmware.
2. Smart Home (KS-811)
The SLH-KS811 is available in multiple variations; 1 gang (SLH-KS811-1), 2 gang (SLH-KS811-2) or 3 gang (SLH-KS811-3). I bought this from Kogan.
3. Shelly products
Shelly products are easy to flash with Tasmota firmware. Shelly provide local control and MQTT support as a result use of Tasmota firmware in this devices is optional. List of AU/NZ certified Shelly products can be found here.
4. Tuya platform products that uses ESP chipset
Majority of the products available in Australia use Tuya platform. Initially Espressif ESP chipset was use in smart devices. Now they switch to non-Espressif chipset. Following chipsets are Espressif ESP chipset which can be easily flashed with Tasmota.