Expose outdoor temperature in climate entity

My mini split has not only an indoor temperature sensor but also a temperature sensor at the outdoor condenser unit. The current setup (midea-msmart) completely ignores the outdoor sensor. Is there some existing support in climate infrastructure for outdoor sensors? If not, can I (ab)use some unused field to store that temperature? I would like to see outdoor temperature plots in the climate entity just like I see indoor temperature plots (current_temperature)
Or would I need to create a completely separate sensor entity for outdoor temperature?