You could break up the circuit with in-line fuses but it would be a big PIA. Maybe if you had a couple RJ45 breakout boards or couplers. And you could probably make some type of breakout adapters for the MTA plugs because you would not want to cut any factory wiring for temporary troubleshooting.

But you said it still blew on MR inspection so I think you should be able to run like that with every plug I listed removed except the selector if you jump con 300 pins 1-2 for INCTM and con 303 pins 1-3 for INHAM.