I bought some cheap Chinese relays that are hard wired behind lights switches (Aubess or a clone of Aubess). Controlling lights is a benefit, but the main reason was for them to act as repeaters. Since installing them, the multisensory they are meant to act as repeaters for are rarely online. One hasn’t been online for over a week and it’s.only about 4ft from the repeater.
So the question is, is this normal with these devices? Or is it a case of ZigBee repeating in general being unreliable? Would more expensive hard wired repeaters do a better job? Or a second bub maybe?
There have been a lot of Zigbee issues in the last week or so, so it all might be a coincidence.
But to answer your question, it’s up to each manufacturer to decide which if any of their Zigbee devices will act as repeaters. For example, sengled, which is not an inexpensive brand, made the decision not to have any of their devices act as zigbee repeaters. Their main products are smart bulbs, and they were concerned that if people turned those bulbs off at the wall switch, the loss of a repeater would make other devices not work. But then they did the same thing with their smart plugs, which makes less sense, but my guess is they’re just using the same firmware in both.
The other issue is availability of parents. But that’s a whole other discussion which to be honest I’m too tired to go into right now.
The short answer is some Zigbee mains-powered devices are repeaters and some are not. It’s not a matter of cost, though. For example, IKEA Tradfri bulbs and smart plugs tend to be better Zigbee repeaters than several much more expensive brands.
BTW, The following is just my personal opinion, there are lots of people who disagree, but if I’m going to wire something into the mains, I will only use devices that have good safety certifications. Which is not most “cheap Chinese” stuff.
Sonoff and Meross are usually a good budget choice. Shelly and Gledopto also.