Most straight forward way to correct a sensor by an offset?

I have a bunch of Acurite 609TXCA temperature sensors. They send their temperature over 433MHz and I use rtl_433 to capture that and the data is sent via MQTT to Home Assistant.

Unfortunately they have a pretty high offset and I calibrated and have an offset value calculated for each.

Unfortunately I am not aware of manipulating data in rtl433 directly, or via MQTT.

In Home Assistant, I could create a template sensor for each temperature sensor and add the offset. But this is really cumbersome, especially considering the large amount of these devices I have.

Is there a better/easier way to solve this?

It might be doable in HA too, but I would use Node Red.
Node Red have the option to capture sensors on a pattern match and to dynamically create a new sensor, so you would just need one simply flow with a look up list.