A check needs to be added to setData() which prevent modifying Built-In profile.
Built-in Profiles are singleton objects and if the user happens to modify the profile data via setData(), the modified version of the profile is returned each time the same built-in profile is requested via getInstance().

It is better to protect Built-in profiles from direct modification by adding a check in setData() such that only custom profiles are allowed to be updated and if it is Built-In profile then throw IAE.