What you call ‘dead stretch’ I call BPFSL— Bone Pressed Flaccid Stretched Length— and personally think that it is a far more accurate measure of length than erect lengths as it requires no cooperation from your unit.
And I otherwise concur with your analysis.
Did I do an analysis? I’m not sure what there is to concur with yet…and that term ‘dead stretch’ was coined long before Thundersplace had popups that gave the meaning of long acronyms like WTFITSTM. For what it lacks in aesthetic appeal, BPFSL certainly makes up in clarity.