How to use Stackdriver datasource with auth type gce and explicit defaultProject?

Hi, I am running Grafana on a Google VM and would like to use ‘gce’ authenticationType but also refer to a specific project (not the one, the VM and its service account are created in).

I see in the sources[1], that using ‘gce’ type causes a project setting to be ignored. Is that on purpose, or can this easily be changed by a small code change?