I seem to remember that having combustible material under a staircase was a fire regulation, so I assume this must not have a CU made from a combustible material is also a fire regulation rather than an electrical regulation.
There are a few places where other regulations impact on the electrical installation, from fitting extractor fans when there is an open flue, to hight of sockets and switches, and how close to corners of a room, the Part L and M building regulations does impact on what can be done electrically.
However as to an ELECTRICAL installation condition report, I would have said that is restricted to the electrical safety and an inspector can not be reasonable expected to include a fire or any other safety inspection, and if he does it could lead to errors and reduction in safety standards.
I last year moved into a new house, and had an inspection done, I was looking for any structural faults before buying, however the surveyor also listed electrical items, and when I said to my wife we needed to change the consumer unit, she said the inspection said it was OK.
OK I know it was not OK, but it pointed out to me what happens if some one considered as an expert lists things out of his remit, the same goes for electrical inspections for insurance, it seems SSE offers an insurance for the electrical installation in a house, and as part of the service there is an annual check, think the insurance costs some thing like £70 per year, which clearly can't cover the cost of a full EICR, however it is a report on the electrical installation condition so the thread I read the home owner was convinced he was getting an annual EICR.
Doing any work on a home where you note some thing dangerous or potentially dangerous clearly you have a duty to point out the danger, but if I can give an example.
In a home with a solid fuel fire which heats the domestic hot water we all know the water header tank should be metal or thermal setting plastic which can stand boiling water, as part of the electrical inspection it is likely we would notice when a thermal plastic header tank has been fitted in error, and we should clearly tell the owner that the wrong header tank has been fitted, but this is not part of our remit, so putting a comment in an accompanied letter is correct, but it should not appear on the EICR.
Be it cardboard stored under stairs, or doors too narrow, or stairs too steep, it is not our job to report, when house hunting we saw some really odd things, we viewed a two bedroom bungalow with 5 bedrooms, but it seemed the 3 bedrooms upstairs could not be advertised as stairs did not comply.
Where I find it hard is when a circuit is locked off, it is so easy to remove the lock after the inspection, but be it drop the tails or fit a lock then never sure what should be done.