As mentioned, it's time to modernize this design a little bit. So first of all, I added the PCB legs from #D1 Mini Tote, and also added footprints for contact switches at the ends of those legs. Then I switched all parts (except for headers) to SMD, because that's usually cheaper and easier to fabricate. Finally, we have some additional headers for connecting those foot switches to the Feather's pins.
The shield remains relatively simple — just a PCA9685 for servo control, and a battery holder with a power switch, and a couple of extra capacitors. The whole thing fits in 10x10cm, so you should be able to order it easily, though some fabs might complain about "multiple projects" in the design.