Autodesk Fusion 360 has a wonderful feature that allows you to determine the center of gravity (COG) of a body. Fusion 360 allows you to measure from the COG to other features of the model but that is all you can do. In my video, I will show you how to add a sketch point, at the position of the model COG which then can be used for any number of modeling processes.
If your model changes in size or shape, you must go through the process again. The point is not dynamically associated to the COG.