I tried both suggested methods and couldn’t get any different results.
I was afraid of that, because to me the Multires Data doesn’t seem corrupt; Normal Map Baking is fine and 1024 Displacement Maps can also be Baked (in 3.3, with a trick).
Have been trying things for a few hours now, with no result so far. I even tried Scaling the head up and down (both in Object and Edit Mode) and although I managed to Bake a 4096 Displacement Texture (when scaling down in Edit Mode), the resulting map was useless.
I will stop for now, but if I get an idea later on and manage to get this working, I will imeediately let you know, of course.
One advice: whatever you do, do not throw your computer out of the window, no matter how tempting that might be!
