Waypoint command labels - pass through to plugin operation

Waypoint has the labelFlags variable as well as the labels that are set on the top level of the app stanza. How can plugin developers get access to those labels? I’m working on developing an istio release plugin for waypoint that would do canary deployment based off a label flag. For example, to release your deployment to 50% of traffic, say:

waypoint release -label=percentage=50

I cannot find a way in the default parameters document to pass these command line flags through to the plugin execution. Is this something that will be possible?