Looking around in the install directory, I couldn't tell what to do. The script is there, but there is a secret version option you need to supply, but I couldn't tell what is supposed to go there.
But, I did find out how to work it on the phoronix forum. The binary wrapper package (.run) also has a secret option, --extract. This is like --keep, but doesn't run the install automatically.
Inside, you can run the installer with the driver version as the first option. But, it's not 13.12, it's 13.251 and I don't know where to find that value. But, if you somehow find that out, you can run the installer.
It's really worse than just running the .run file...unless, say, the driver is broken and you have to patch it yourself!!! Which is the case with 13.12. Somehow, AMD left off a patch that was included in the beta driver. Anyway, the phoronix community seems to keep up on this, so I'll start looking over there for help.
I cannot believe the situation is as degenerated this much. It was bad 10 years ago, but who would have guessed it would actually get worse, not better. It's astonishing.