SharePoint Forms w/ Asynchronous Workflows
Run Workflow Asynchronously (Improve Performance)
If your form is submitting to a list that has one or more workflows, you may run workflows asynchronously. When running workflow asynchronously, the workflow(s) run in parallel with the form submission process and these workflows often take much longer to process than the form submission. This will allow the form to post data without waiting for the workflow(s) to complete. This can improve the end user experience when a form is submitted by decreasing the wait time.