I am considering getting a smart lock, seems like the Yale Assure would work well (both BT & Z-Wave).
One thing I haven’t figured out is could I use it for presence detection?
The case I am thinking about is I want to give access to my house to a sitter. I can give her a key or a code to get into the house. But I would like to know when she leaves. I don’t think this helps at all in that respect.