Allowing multiple Person type usages

 Hi there, I'm currently facing some reporting problem (duplicated records or new types such "Employee - Ex Applicant") while finding Employees with more than one valid person type at same date. We don't care if an employee was previously an Applicant: he currently is just an Employee. I saw that we can delete unwanted person type only by deleting table record on per_person_type_usages_f.
Did someone already face and work out the issue? What way to take: user hooks?
Thank you.
Regards,
danton