Hey Robert,
Thanks for reaching out to us!
You don’t need our PRO plugin for the Tickets plugins to work. You’ll just need our free Core Events Calendar plugin as well as the associated shopping cart plugin for the Ticketing system that you chose to get the full features for the Ticketing plugins.
I took a look at our internal tickets for the integration and it looks like that feature is currently on hold. It has been worked on and it looks like it will be addressed again in the future, however I can’t give a set date to when that would be available.
Thanks!