I'm just going off of what Greg Pease and other reported experts have written. I know it was a big enough task and PITA to pack what I have in jars and mylar without adding vacuum sealing to the equation. To me, the aerobic adding makes sense. I've opened enough jars that are 3 to 11 years old, that weren't vacuum sealed, to see the results were favorable. Optimum? Treated like it but I can't say for certain. Optimum enough for me.
Optimum for me is smoking something even just a few years old and comparing the price I paid to the current price. Even more optimum is if the blend has changed or been discontinued. I KNOW that improves the taste of the tobacco.