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The workshop concluded that there was no danger to reverse profiles for recreational divers...
There have been several studies on the topic that showed either no effect or a dramatic effect.
There as a major workshop on this topic about a decade ago, with experts from around the world participating. No one knew the origin of the prohibition of reverser profiles. The earliest reference to it was a suggestion in a 1972 PADI manual, but PADI (who participated in the workshop) could not identify who put that suggestion into the manual or why. Over time the suggestion somehow became a rule.