Thanks for this explanation, Mark.
To me, this still begs either the question "what causes potential verification failures that requires us to add 0.1% to our measurements"? - or, if a certified course produces a record, and the the course is run as certified, why add 5.28 feet per mile"? For a marathon, we are adding 138+ feet to the course with the SCPF.
Not challenging this rule, or the reasoning behind it. Just interested in the philosophy/rationale behind it.