You may use the latest version of my configurable firmware with Sonoff Basic ZBR3. But only one external sensor is tested (Si7021)
This firmware allows you to create a Zigbee switch device with a flexible configuration of inputs and outputs. I’ve created a base firmware for CC2530, CC2530 + CC2590 , CC2530 + CC2591 and CC2530 + CC2592 chips. The attached configurator for Windows can write your device configuration to the selected base firmware. Then you can save the customized version to a separate HEX file and upload it to your device.
Inputs and outputs can work independently. So you may create a switch without a control button, or a simple button only.
The device with this firmware also works as a router.
Note: the firmware is designed for constantly powered devices.