HTTP Sensor - unit of measurement

I am looking at build a bit of software that calls the HTTP Sensor module and the “state” field will be populated with the Current Pogram running on a particular TV Channel. Just wondering if I can use the “unit of measurement” field to be populated with the Next program to be shown or even leaving it blank will cause an issue.

Or is it possible to insert my own custom field called “next_program”, but not sure how I would show this field on custom-button card.

I would prefer to do this method, as then I do not need to write a plugin within HASSIO and instead this would be a plugin of the MediaPortal TV Server.

Thanks in Advance