One thing we are working on right now is something similar. We are able to pull an export from our HR software that we are uploading to a SQL database. Within the export we have all of our Active employees and who their supervisors are with a unique identifier for each one. When the person fills out the form, we look to see who their supervisor is and then do a second lookup for that unique identifier to grab their network username. Since we are using that username as the same username in Laserfiche, we are looking to see if we can then assign a task based on that value. I'm working on that part today, so I'm not sure if it works. If this works it might help you get around creating a user task for each person and instead assigning dynamically, at least for the first part of your workflow.