What the existing connection tells
A screen in the living room can be quickly seen, while a hallway is quieter. In a large house, one indoor wall can actually be too far from the bedroom, office or back door.
A indoor mailbox works well when it is hanging on the daily walking route, but placement also requires attention to cable, power and privacy.

A screen in the living room can be quickly seen, while a hallway is quieter. In a large house, one indoor wall can actually be too far from the bedroom, office or back door.
See who is especially open, where existing doorbell wiring comes out and which places are not logical due to moisture, direct sunlight or an inconvenient walking route.
Choose a main position and determine whether an additional indoor post or app access is needed. Keep the controls at a comfortable height and plan cables before the wall finish is closed.
Let residents answer a call themselves from the chosen location. Check the sound volume, screen visibility, and whether the doorway is comfortable to operate without walking to another room.
Yes, if visibility, privacy and cable route are suitable.
No, but a fixed indoor post can improve reliability and operation at home.