I guess you could, but if you file yourself then to refile you have to file an Amended 1040X return. Actually I don't know if you can add Full Service after you file. You should try to file right the first time.
What is LIVE Full Service
https://ttlc.intuit.com/community/choosing-a-product/help/what-is-full-service-by-turbotax-live/00/2...
To cancel FULL SERVICE an expert employee said…..
To cancel Full Service, you must go to the initial meeting and indicate that you no longer want the service or contact support directly. Clear & Start Over will only work to downgrade products (like TTO Live to non-TTO Live, or Deluxe to Basic) but not to cancel Full Service.
