Deactivate snapping in a workflow?

I have users editing a feature service, where they can enable snapping and also pick the layers to snap to, using the CreateNewFeatureControlRegion.  However, I have a workflow where I need the user to select a road, which I do not want the user to snap a record of the feature service to, so it is not selected as a 'snappable' layer. How can I disable snapping on the fly in a workflow? I have tried several variations using the Run External Command with commands like 'DeactivatSnapping' - without any luck.