I have some custom form elements that only make sense if the editor remembers to add a custom workflow to the forms, where these elements are used. I would like to validate this to avoid that the editor creates a form but forgets this workflow. I decided to do this on FormPrePopulate (which is maybe not ideal.. but it seems to work)

But what should I use instead of the obsolete property WorkflowIds?

Or should I use a completely different approach. For instance validate when the editor saves the form if this is possible?