1. This is how I would consider the interpretation of this layout plan:-
2. A physical way of finding the centrepoint or "the centre-of-gravity" of this unit is to first paste a copy of the layout plan onto a cardboard. And try to balance it on a nail.
2.1. Personally, I use a quick "eye-ball" method + logic to figure out the centre-of-gravity.
3. Frankly, many of us would often not imagine or look for protrusions. But rather looking at a "dime of a dozen" missing sectors.
4. For condo units or high rise units, often the logical method is (usually) the readings from the living room (side) looking out towards the windows or balcony:-
4. If one wants to take a reading from the main (or front) door. It is quite like standing inside the main door looking outwards. If you are particularly a follower of the front door.