Correct. I just use HomeKit automations to sync virtual switches to HomeKit only devices. In my case with the Xiaomi Aqara hub, that includes Xiaomi Zigbee devices that are paired to the Aqara Gateway.
I do all my automations in Rule Machine or one of the HE apps. I used to use a mix, but that became a pain to manage since I would sometimes have to rebuild the HomeKit automations if something became corrupted and I lost them. These days with Controller Pro for HomeKit, that’s less of an issue sunce I can backup HomeKit with it, and Homebridge is also now very stable. But I still prefer automating everything in HE and only using HomeKit to sync with virtual switches.
For HomeKit temp/humidity devices, there’s no way to use them with comparison to another device’s measurement, You can only compare against a set value in HomeKit. I know of no way to sync a HomeKit temp/humidity device to a virtual temp/humidity device. For that reason, I keep my Xiaomi Temp/Humidity/Barometric Pressure sensor directly paired to HE, so I can compare humidity against a reference device for my bathroom exhaust fan.
