The aging process is broken every time the seal is broken. So if you want your lb of blend "Whatsis Imperial" to age while still being able to enjoy some along the way, breaking the lb into smaller amounts and then jarring them allows you to do that without disturbing the aging process on all of it.
Jarring for long term aging requires a reliable airtight seal, and that means a mason jar. Pack each jar as tight as you can, compressing the tobacco as solidly as you can, and leave about 1/4" of air at the top. Some people like to warm the jars just before sealing to lessen the air pressure in the jar. A little air is needed to allow the bacteria to start their beneficial work before they absorb all of the oxygen and croak out. This leaves the anaerobic fermentation environment suitable for long term aging.
To age or not to age, that is the question.
Aromatics do not benefit from long term aging. So if you like aros, buy 'em and enjoy 'em.
Latakia peaks and fades. It's probably as it's strongest for the first 15-20 years, then it begins to "soften". By 30 years it has WAY softened, and by 35 years it might as well be dead. But many smokers actually prefer the flavor qualities of softened Latakia. I just figure you can do as well by buying a gentler Latakia blend in the first place and save the $$$ on buying faded "classics".
Virginias also eventually fade, though their lifespan is considerably longer than Latakia. Of the 40 - 100 year old blends that I've smoked, Virginias do seem to croak out after 60+ years, and go positively strange in flavor. The only exception to that was a sample of Capstan from 1941. That still tasted like Capstan - in a miniaturized way like all really old blends - but it didn't stay that way for long. Exposure to fresh oxygen caused it to quickly deteriorate. Really old tobacco seems to be pretty unstable, so if you open a tin smoke it up quickly or reseal it quickly and pray. That $150 that you spent could be sludge the next time you go for a smoke.
Burley seems to be the aging champ. In the 100 year old blend that I sampled, it was the only clear note that arose out of the sludge.
Are blends ready to smoke when released? With the possible exception of some of the new blends that claim to be "designed" for aging - a marketing gimmick if ever there was one - blends are ready to smoke when released. But I find that they do benefit from some extra time on the shelf. A couple of years allows blends to ripen a bit. It might be that nothing more than that a little homogenization of the components has taken place, but I like the effect.
One of my favorite blends is Escudo. Its flavor does change with aging. The Perique goes from peppery to fruity giving the blend a flavor that is less bright yet has greater fullness and depth. It still tastes like Escudo. Aging isn't going to change the basic flavor profile into something completely different. The differences are subtle. Fortunately, I like Escudo fresh and aged, so I can enjoy it now while some sits on the shelf aging in a wonderful way.