VRM alarm rules - negative temperature value

I have imported a virtual temperature device into VRM, a freezer temperature. I actually did this using rednode and a shelly temperature device. This transmits the temperature value to the cerbo via MQTT, though the site WIFI network. The Shelly device is about 400m from the cerbo unit.

I would like to create alarm using the VRM rules but with negative values. That way I can tell if the freezer is operating. I understand that this is not the intent of VRM but I have 6 installtions of VRM that are in this category and it works amazing. Such an amazing product.

The current GUI does not allow for negative values to be entered.

Could we add this into the alarm creation rules for temperature values?

Thanks in advance