Thanks. That clears it up a bit for me. What was confusing is I was assuming ALL proof ASE
coins issued by the mint were of the same grade, i.e. perfect--PR70. To me, that brings up the question of what makes the difference if it's still encapsulated in the OGP. Can't be handling/exposure by whoever happens to own the coin since the coin itself hasn't been physically touched. Must be the mint. Not necessarily something they are doing wrong but something they are doing "different" for the ones that qualify for the PR70. Or is it just something inherent in the minting process that no one has any control over?
I'm not sure why, but another assumption I was wrongly making (given your responses) is that NGC was the be-all end-all, top dog when it came to coin grading. Apparently the grading standards of PCGS must be quite a bit higher.
I only own one single proof coin in the OGP with COA and I haven't tried to remove it, nor will I but if I suspected it might be a PR70 (Don't have the expertise) and submitted it for grading, would that process involve removing it and possibly devaluing it by its removal? Would I have a lesser valued coin if it didn't meet PR70 standards?