Some ideas to improve the Face Detection workflow.
When manually updating the name of the suggested person, the text pop-up is too narrow. It could be double the width to minimise truncation of the whole name. The width should probably be based on some localisation settings or be content driven i.e. match the widest length.
Additionally, the text pop up could be enhanced with at least one thumbnail to help me identify the person. It could be optimised to help the photographer choose more powerfully with either text or image.
When in the Faces view and you are asked to confirm faces, it would be good to understand context and actual size of the person in the photo. People in the background who are slightly blurry are possible options. However, you want to make a decision about whether they are validly defined in the photo. It's hard to do from uniform rectangles, noise from low light and pixels from being far away aren't easily distiguished.
There are two scenarios 1) you are screening photos and have a do not publish list so you need to filter out people, even if they are in the background, 2) you are trying to assess whether the face is actually the subject of the image rather than a bystander in the crowd. They are quite different scenarios with opposing needs.
I've mentioned this one before but Faces don't need to span the entire catalog. In many cases, the photos for a particular photo session have a finite closed set of faces, having the universal set makes the process inefficient. I might want to borrow some Faces from another folder but I should be able to choose to do that. A user scenario of event photographer should be considered - there are named people in my collection that I photographed 3 years ago that I will most likely never photograph in the next 5-20 years.
If you manually define a face rectangle, the system doesn't take an educated guess immediately (even on an M1). You have to manually type. There's an opportunity to deliver a quick visual cheat sheet based on the faces in the current collection (the first step is enhancing the pop up). I don't know the hundred or so people I photograph at an event, the interface needs to help me appear to be totally familiar 😀 - that's what UX design excellence is all about.