Quick switch between Internal and BT GPS

The idea is to have the easily accessible setting to switch between internal and already configured external BT GPS. When using this switch, BT GPS could stay paired, but internal GPS would be used instead of BT GPS.

It is for cases such as drained battery of external GPS, when you want to compare the position of both devices or when you have the external device somewhere on bike and you are looking for the cache only with mobile :)

Would it be useful also for sb. else?