To run a true 24 hour aeromedical operation you need to have the pilots to do it, and includes allowing for proper staff numbers, coverage of sick leave, annual leave, training, extended tours of duty if Pearl operate under CAO48 concession, late night operations and the fact of when the airlines go into recruitment mode you will lose staff.
I heard that Pearl were short of drivers, because the training pilots were line flying with the new guys to get up the night experience requirements. Didn't Pearl have a couple guys leave during their endorsements?