@Royski What's your long term experience with the Conbee 2 and Xiaomi devices? I just added one tonight and it works fantastic with my Lutron Connected Bulb Remotes on HA, which I'm syncing back to HE. So now I'm thinking if I can add all the Xiaomi sensors to the Conbee 2, I can stay at just one Xiaomi hub (for my Xiaomi buttons) and still eliminate my HomeKit automations I've been using to sync Xiaomi sensors to HE.
I'm using ZHA with the Conbee 2 just as @stephack is, instead of deCONZ. Not sure that's going to make a difference. Seems more the radio that's made the difference over the Nortek already.
Interested to hear your thoughts and long term experience with Xiaomi on the Conbee 2. Thanks to this fantastic new project, I now have a way to use the HomeKit Controller feature in HA to get Xiaomi HomeKit gateways and any other IP based HomeKit device, plus whatever else the Conbee 2 will pair to HA, back into HE. So it's not the end of days if it doesn't work well, but I'll be the first to admit that my obsession with connecting different systems is getting a little out of hand, so a reduction of a least one gateway can be considered progress. 
