This solution is not a good solution because it requires you to add any new forms to the workflow each time and is labor intensive and leaves room for error if you miss adding a form to the workflow. We need a solution for this also.
Here's an example: Our sales team attends approximately 30 different conferences a year. We create a lead gen form for each conference so that we can effectively track which conferences we should be attending/exhibiting (high expense involved as everyone knows). We need to report on how many conference lead became a deal in the sales pipeline and how they are progressing through the pipeline stages, etc. It would be much easier to be consistent in our form naming structure for the conferences and add the contacts to a report and/or list using automation "if form name contains 'conference lead' update 'conference lead' property = true" ... or something like that.
@Phil_Vallender solution will work better for us. Still leaves some room for error but is doable.