Whilst I have no knowledge of the certification process, I can't imagine that running on one cylinder less would be part of it.
There are so many different ways a cylinder could fail, from valve problems to the ever favourite cylinder coming off and leaving large lumps of metal flailing away. It's pretty difficult to replicate failures as there can be so many variables. It easier to to say it either works or not!
One dodgy mag or plug, shouldn't lead to there being one cylinder not working, rather one working slightly less efficiently, afterall, that is why we have a dual ignition system. Even if it is a decrepit, old school solution.