With this much debate going on, the choice (for this situation) comes down to the employee and the company itself. Is is better to error on the side of caution in case of an unlikely event? Or is that going too overboard?

Just an idea but I believe the equipment manufactures should be providing some assistance here. As others have noted this has been debated over and over many times. At this point it’s all an opinion and how much risk is one willing to take.

I believe, given all the arc flash attention now days, the manufactures are the ones who should be do the testing to help answer these questions. Will the doors stay closed on brand X equipment given a fault? Will their disconnect, motor control center, switchgear, or panel blow apart or stay together? In my opinion, more testing and less speculation is the only way these questions will ever be answered.

I agree with SCGEng1 in that the manufactures should be involved with more of the testing. However, that testing should be done on 'real world' equipment and not on things directly off the assembly line. The tests should be done with panel covers that only have half their original screws or are held on with sheetrock screws, or safety switches which have sprung doors and bent hinges. (IMHO)

I see failed enclosures after an arc flash all the time on real world equipment, I am usually the guy providing replacement matching sections.

I can see parts of both sides of the opinions. But wouldn't a better car comparison be to strip the car down to a model T and then go on the highway. I'm sure all of us and all the other drivers don't go out and intend to have an accident.

All of the components of the car; steering, crumple zones, air bags are analogous to AF PPE being worn. Will the vehicle safety systems protect you 100% of the time, no. You can survive many crashes without life threatening injuries.