Using Ctrl-A / Shift-Enter to bulk accept suggested photos works well until the number of photos for a particular person grows large enough.
On a high-end build, I find that there is a visible delay (5-10sec) starting around 10k photos and it only gets worse as the picture count grows. At 20k photos, it can be easily 20-30sec. At that point, it becomes easier to scroll back up to the first suggested photo and shift-select suggested photos.
It would be great if there was a version of Ctrl-A “select all” that only selects suggested photos that could be used to more quickly select and confirm all suggested photos.