Is it possible to have a variable value for Volume Triggers when doing notifications

In short, I'd like to add multiple thresholds on a traffic sensor and at each point have it show a custom message, e.g. "Device XYZ at branch ABC has used 25GB via its LTE Link", but so far have been doing it with a custom notification template for each threshold as the message variables don't seem to include a volume option.

Current message reads: %device %shortname has reached 25GB of total traffic usage via LTE

Ideally I'd like to add something like: %device %shortname has reached %volume of total traffic usage via LTE

Thanks in advance.