@Luisfba ~ there was a DISer who did this when his booking window opened at 60 days out. He grouped the phantoms with an onsite person to access the 60 day window. Then he moved the actual person back to the "real" people group.
The FPs, which were generated by a single ticket (NBFP), remained within the system for him. I believe he was the only one who tried this.
In your case, purchase the full set of tickets for your next trip and book for all the days as GLFPs. Then you won't have to take vacation time playing on your phone although it appears you'd have fun doing this!