I think I have a handle on the Shutdown pin; it looks like a nice, power-saving Mute button. Thus, I've put in a Jumper to allow the user to take its signal from D12, or just sit on the Ground.
Other than that, I've more or less left things as they were.
I'm contemplating replacing the TFT components (the resistors, anyway) with SMD versions to reduce space, but I'm leaning against it. I'm not sure how much benefit it would bring; and, from what I can tell, hand-soldering would be a pain in the keester.
That, and the aligning of the Feather-related headers and mounting holes, are basically just "design tweaks." Unless someone posts something about it, I'm done with adding, changing, or significantly rearranging the actual components.