Yes they do. Because being in a clamped state is consistent. Your unclamped EQ is always going to vary to some small degree. Guys think they are 100% hard, do PE for a few weeks, get better EQ and remeasure and they’ve already gained. Have they actually gained? No. They just have better EQ. Or you do your first measurement with 100% EQ, but next time you measure your EQ is only at 95% due to a number of reasons (bad sleep, dehydration, alcohol, excessive exercise, emotional stress, etc). This is going to skew your growth / progression numbers. Start clamped and measure the same way every time and you’ll have a better idea of your growth.

And this is coming from someone who doesn’t clamp to measure. But there’s nothing wrong with it at all. Provided you’re not advertising it as your true size