rtGradleResolver and rtGradleRun: How to define multiple repositories?

[Pytry]

Here's the situation:

I need to resolve from multiple repositories.
The repositories will be different depending on the stage of development for the project (e.g. dev, uat, pre-release).
I do not have control over the Artifactory group repositories, so I cannot create a group for each scenario.
I'd prefer to just rely on the repositories defined by gradle and use an init.gradle script to control what is being used.

Is it required that I include a resolverId when using rtGradleRun? If yes, then how can I define multiple resolver repositories when using rtGradleRun?

[Pytry]

This is for a Jenkins pipeline using declarative syntax and the Jenkins Artifactory plugin.