....So the topic of KAIC for control panels has been spoken about at length here, with the general consensus seeming to be that there's no way to accurately determine what the worst case fault might be. This is generally due to the myriad components used in a typical industrial control panel creating an astronomical number of possibilities for an arc flash to occur.

With that in mind, my question is regarding AFC where power distribution blocks are used right after overcurrent protection in a control panel. See the attached grainy pic for context. We know that impedance is our friend when it comes to inhibiting fault current. Is there even any way to calculate what a power distribution block would do for limiting fault current in a control cabinet, let alone justify using those calculations to determine AFC in the panel? Would you guys even recommend considering this in the calculations at all?

For example, the pic attached above shows #1 THHN Cu conductors landing on an Allen-Bradley 140U-H2C3-D12 A 125A breaker, then about 7" of #1 into a (100KA-rated) power distribution block.

Everything coming out of that block is #10 Cu. Is there a case for arguing that one could incorporate the longest/shortest/median length of conductor coming out of that block into the model? That shaves 4.5KA off the AFC in that panel. Would you have to consider a possible arc could happen across multiple conductors in a phase? Or does the reality of varying impedances due to the scores of different wires in the panel render any such ideas meaningless?