How to get around the completion item limitations on forms

Hi everyone! We currently have a "Lead Submission Form" used by our customer service reps (CSRs). When they receive inbound calls, the CSRs fill out the Lead Submission Form and choose a sales rep (custom field). I have completion items that assign the user based on what is chosen in the sales rep custom field. I also notify the sales rep chosen. I'm currently at my limit of completion items, but I have one more sales rep to add. Am I missing a better way to do this? I have tried to go the engagement studio route, but it's required to add a recipient list, and I'm not sure what to put there... Any suggestions are welcome! Thank you!!