That’s a very good idea!
It is possible to get a gps lock indoors sometimes, and the results of going to rtl can be rather embarrassing to say the least 
Plan your flight and know your risks
Unfortunately with the 4.1 update every user will have to manually change the EK3_IMU_MASK to 7, because the default is 3. The EK2 parameters are not copied over to the EK3 parameters.