I swapped out one of the #8 screws on the ground block with a cap screw. I attached the power supply ground to the other screw on the ground block and powered up the panel again. Everything still works!
I started on the wiring, with cutting off the insulation on the OAT wire and crimping Molex connectors to the wires. Unfortunately, I didn't read the Dynon instructions properly and plan on installing the shielding and the other ground wire from the EFIS. I also need to properly crimp the Dsub connectors by using the E crimper for the wire crimp and the B crimper for the insulator crimp.
Ground wire from power supply connected to panel ground
