When I noticed that there was quite a gap around the shifter boot at the bottom, the brace below it was sagging. I took the console off again and looked at the shifter boot. One side had been stapled wrong at the factory, but the other side was sagging as well.

Adding this brace below eliminates the sag.

The front of the brace loops around the front bracket of the boot before it's attached with a couple of loops of upholster's thread (or any thread) through the two holes at the front of this brace; the rear part has holes to line up with the OEM screws that hold boot and coin holder in the back of the console.