@Daniel_Dawson, thanks for looing into my project. I hope that we can help each others. For your grow tent, I think there are a couples solution that we can do.
The module have UART expansion. You can add an Arduino. I have an example above on thread 414 connecting to DS18B20 as an example. We can replace the DS18B20 with any sensor you may need. There are many Arduino sensor out there. A bit of coding is needed to package those data and send it back to the hub.
Another option is to use Bluetooth. I have a daughter Bluetooth card that connect to serial port. It act as a BLE gateway. One of the device that I have supported is the following device. If you do not mind going to ebay, these sensor is known as Xiaomi Flora. It comes with Moisture, temperature, fertility and illumination.
The battery live is surprisingly excellent. It has been a couple years. I have not replace the battery yet. The range is not that great. Depending on the size of are of your pots and how open it is, you may need a few gateways. The gateway can listen to multiple of this “flora” devices easily.
Here is a video that I made. The video is made on Hubitat hub which has very similar framework to ST at this point. Please note as ST is moving on new path. I am not sure yet whether I am going to support my devices on ST. I have to see how much time and investment that I need to make for my device to work in ST in the future.
Let me know whether there are some of the solution is close to what you can work with.