Yes, and then some.

Ok, here are some I've heard. For some reason, the ones I remember best have to do with strings...

A string caused a longbow limb to twist.

Just changing the string gave a 4# increase in draw weight. I.E., with string A the bow pulled 60@30. With string B, it pulled 64@30 .

A bowyer who voided the warranty if you used a dacron or flemish string.

A bowyer that said flemish strings are "less accurate, and can be dangerous".

A guy saying "for every inch you pull past 28", you gain 10# worth of performance". He wouldn't answer when I asked what would happen if you pulled a 40@28 bow to 24".

A claim of making up to 20,000+ strings on a wood jig. This one probably won't make sense to folks who don't make strings. First, think about the number--that's averaging 1,000 strings a year...almost 20 strings a week, EVERY week, for 20 years--from a guy who doesn't even sell strings. Then, if you have ever used a wooden jig--you'll understand how funny the claim is. I wore one slap out making a couple hundred. I don't think my Dream Machine (stainless uprights and uni-strut) would begin to hold up for 20,000.

I'm sure I'll think of others.