Add more than two metrics with transform data?

Hello everyone,

i am using Grafana 10.2.3 and influxdb2.
I would like to monitor my electricity consumption in Grafana and I have one metric for the total power consumption as well as several individual meters. Now I would like to subtract all known individual meters from the total consumption. I currently do this via transform, but here I can only process two values, so I currently have 8 transformations to subtract one value each and then this sum from the total consumption.

Can I do this better?
Thank you

welcome @stefmat78

balance is key here, 8 transformation sounds unmanageable

I try to do everything I can in the source data using it’s querying language. I try to avoid transformation if at all possible