Maybe I missed it, but couldn't figure out - what contact sensors?
Sonoff SNZB04. They don’t seem to be as fast as my Samsung, or Iris contact sensors, but they were $6.95 each and have been trouble free for about 5 months now. I’m using them on bathroom and shower doors to keep lights from shutting off, turning on exhaust fan, etc.
There’s an update available for the Sonoff routers. It mentions a fix for xiaomi devices (I don’t have any personally) for anyone interested. I installed it on 2 of my routers without issue and will update here if anything good or bad happens.
I’ve updated the rest of my Sonoff repeaters as of a week ago without incident. I haven’t seen any identifiable difference, but I had zero issues before the update, so maintaining the status quo is good.
Looks like Aeotec has a Zigbee Extender hitting the market.
I got a couple back when they first came out to help bridge stuff between my house and detached garage - they route well.
A plug or some other mains-powered ZB device would likely work just as well in my case, but both spots happened to be high-mounted outlets that weren't useful for much else, so I figured I'd give the Zi a shot. No regrets.