I've heard that vacuum sealing causes volatile terpenes to evaporate more readily due to the shift in atmospheric pressure. Has this been true in your experience?
I've read that as well, but it has not been my experience with weed or any other dried herb or vegetable I have preserved in this way.
Nor has this been my experience with traditional canning processes that naturally create a vacuum seal.
Vacuum sealing completely seals the the jar airtight. No odor escapes the jar but the contents are fresh and fragrant upon opening. You can test this yourself with any jarred food from the grocery or home canned food.
how well do the oxygen absorbers work? Could they be considered a substitute for vacuum sealing?
The oxygen absorbers work pretty well. They do remove the oxygen and when you open the jar you need to pop the seal to open it. It would seem to be a redundancy to add an oxygen pack and then vacuum seal, but it works great. I picked this tip up from prepper techniques to keep dehydrated food fresh long term, like 10 - 30 years.
You can use just an oxy pack but they can only absorb so much oxygen. Because a volume of air is involved in a jar as opposed to a Mylar bag for example, the oxy pack wears out quite quickly. If you remove most of the air by vacuum sealing,the Oct pack can take it the rest of the way and will last a lot longer. You will notice that the oxy pack is still good when you later pop open the jar.
I believe Boveda Inc has stated that we shouldn't vacuum seal a container if it has a boveda pack in it?
I think they are concerned with them bursting but the jars are not vacuum sealed to that extreme. It may be a concern with aggressive bag vacuum sealing though.