When we want to know the effects of certain Firefox changes to improve privacy, we can make the changes in an arm/variation of this shield study add-on, so we can measure the effect of the changes via Telemetry.
To see what the add-on is studying, check the studyConfig.variations in
lib/study.js.
The easiest way to run the study add-on is with the shield cli.
npm i -g shield-study-cli jpmshield run . -- -b Aurora
You can also make shield start Firefox with a certain variation:
shield run . <variation> -- -b Aurora