In my opinion this would require a written amendment to the NEC, not just the whim of the AHJ.
I completely agree for an optional interlock that is part of the panelboard manufacturer listing. Any other interlock is completely subject to AHJ approval without ammendment, IMO (even though the design may be identical to a manufacturer listed one).
I think the basic point is that you can't stop people from screwing things up and inspectors should not be enforcing 'what ifs'
You can stop people from screwing up to a degree, but otherwise I agree it is impossible to make anything completely foolproof.
I did say "perhaps a stretch", did I not? Inspecting must take some 'what ifs' into consideration. One example, determination of 'subject to physical damage'. Many Code requirements force the AHJ to ask the 'what ifs'... and yes, they sometimes go a bit too far!!!