The last 64k can be read like M4.3.
32k-64k in first half is possible with higher voltage.
First 0-32k require short circuiting an address line and reading 32k-64k.
So not very practical or safe, but not totally impossible.

In vtls post you can see the two command lines used at the top. He is using gcc to compile seed-gen.c source code into a program called seed-gen. In the second command line he is running this program from the current directory (.) with a known good pair of seed and key to get a list of all the pin c...