That can be done. Relatively, it would be an expensive operation to create the sensor because it would require an additional process to be created and an external binary to be run each time. After initialization, this project runs entirely in bash and only calls an external binary to adjust the fan speed when required.
I will look into it. It would be a floating sensor at the top of your Lovelace, not attached to a device. It would require, at a minimum, calling an external binary such as curl to perform the data transfer. I’d like to look at using NetCat though because it’s included in the base image. How often would you like it updated, btw?
Getting the temp, though, is here: New Addon: Raspbery Pi Temp Sensor!