Ok, because in that picture it looks like the rear brakes are barely doing anything, you can still see the original rotor texture and after bedding in that should be entirely gone where the pads ride.
The 10.7’s are a Mustang cobra caliper, the parking brake uses the caliper there’s no separate pads or drum.
I thought the same thing about being able to get a few more clicks when the brake pedal is depressed, but honestly when I tried setting the parking brake with my feet on the floor I realized I had much better leverage to pull the handle when I was stepping on the brake. And I’m pretty much always stepping on the pedal when setting the parking brake so the difference didn’t occur to me. Not saying there can’t also be an adjustment issue but there’s definitely a leverage difference.