That should save whatever the plugin query param is as the submission for the “plugin” field, which is the key for the relevant field.
I think this should actually be moved to be a wizard-level feature though instead of a step-level one. Currently you have to visit the actual step it’s applied to directly for this to work. It shouldn’t matter which step you’re currently on.
There should also probably be a list of permitted values.
@merefield Maybe something for you to take a look at when you have time. It’ll be good to have a second pair of eyes on this feature.