IMO, yes it was a mistake. IME using a SAAMI reamer, the bearing surface of the 108 ELD has less than 1 caliber of shank (depending on lot number) in the neck of the 6mm Creedmoor when it contacts the lands. Using AIAW mags, I run out of neck long before running out of mag length. IMO the SAAMI 6mm Creedmoor throat length (considering the shallow leade angle) is not optimized for long, pointy 6mm bullets.
I think you may have mixed up your scenarios a bit. A short throat with steep leade doesn't allow rounded-nose bullets any room. A long throat with shallow leade angle doesn't allow long, pointy bullets to contact the lands before running out of magazine length (or if mag length is generous, then you run out of neck length to hold the bullet shank). I understand your point about longer throats, and this was a valid concern 20 years ago when bullets were shorter and more rounded than they are today. BobinNH used to chamber the 7RM with a long throat for just that reason (to seat the base of the bullet shank at the base of the case neck, often using NP or BBC bullets, IIRC). The point I was making is universal and does not "depend". When comparing bullets with long, pointy noses to bullets with more rounded noses, and assuming equal leade geometry, the pointy bullet needs a shorter throat to contact the lands at a given OAL than the rounded-nose bullet does.
