Workflow - Resubmittable Forms / Hide Completed Steps

Summary:

I am configuring a workflow with Main steps that are the basics required for completing an activity (that must be done in sequence) and Sub steps that can be done at any time spanning a few of the Main steps' sequence. The flow is therefore mainly linear with some sidequests to be completed at some point before Ending the activity.

1. Completed steps are always still showing in the workflow. Can the "Show Available When" section also force completed steps to be hidden? I haven't managed to make this work. I would want to hide steps from the workflow once done and only keep the available steps visible.