With my a7r3, I also like using Spot Metering tied to Focus Point Link so that wherever my Flexible Spot focus point is, it will meter for proper exposure at that point. I think this is very useful for portraits or images of single objects.
Note too how multi metering works when Face Priority is also selected.
From the 'Help Guide'
forum: Sony Cameras
This is totally how I have my rig set up. It's very, very handy! It eliminates the need for exposure lock/recompose like I used to do with canon cameras.