If you can’t easily get TRÅDFRI repeaters or outlets, these are said by trusted sources to work as decent little Zigbee repeaters and they are compatible with Xiaomi also according to the sources. Disclaimer: I have no experience with them personally, but I trust the people that claim they work for that purpose.
List of Good Zigbee Repeaters?
[Edit] And I see now looking through the thread myself that you posted there before and you are in Australia, so those are the suggested option for you, otherwise importing TRÅDFRI outlets and repeaters is excruciating expensive. You’d be better to try and set up an XBee for that money. Especially if you live in one of those Australian concrete fortresses That block all signals I hear so much about 
