Is it possible to limit the amount of times a user can submit a frontend form to create a new post? My scenario is that I'm building a sort of membership/listings site where a user will sign up, pay for a membership plan, then fill out a front-end form which creates a post in the directory custom post type. I then only want them to have the ability to edit their post they created with the submission and not submit any new posts. Is this possible?
Also, do you have gravity forms integration where I could use Gravity Forms for the frontend form submission instead of the MB Frontend Submission
Yes you could do this by using some of the hooks, to check the author of previously entered forms and maybe a redirect if one has already submitted a form. You then would need to set the user role caps for the custom post type so the user can only edit own. You could create a filter on the archive query that only retrieves post from that user too.
As far as GF integration, its my understanding that this is the point of frontend submission and with the rest of the metabox conditional extensions you could do most of what gravity does. Only thing you may need is a notification system for email notifications.