Some years ago this "dragon" raised its ugly head with three different classes of "one design" cats that we were manufacturing.
To keep things short I will only relate about one of them. (although the same/similar applied to all three)
We manufactured a 5m cat that could be sailed one up on trapeze cat rigged or two up on trapeze as a sloop rigged.
Before we released it for commercial sales we fully tested it in both forms sailing cat and sloop against each other for several months and although in it's different configurations it performed differently on different points of sail and wind strengths, we found that over a full range of courses, wind and sea conditions its performance in either configuration was not detectably different enough to warrant any difference in rating. That didn't stop "the powers to be" at that time from allocating different yardsticks for the two different configurations which had the same detrimental results for them at regattas (being placed as different classes) The Association that had formed around these cats decided that this was just not good enough and wrote to the yachting association responsible for the yardsticks to point this out to them and "insist" that all future ratings for this cat, in either form -cat rigged or sloop - had to be the same. With that pro-active representation from the "official" association of the class the yachting authorities readily agreed and the problem was solved.