Nice idea,.. but not going to help much in an earthquake.
The jars may not fall,.. but the oscillations will slap the jars together ( I believe) and they will break that way.
If in a earthquake prone area, store by the case, with foam or other separators on a shelf that has a lip.
depends on severity on which type of Earthquake. Our most common ones just shake a bit and would cause a jar to "walk" off a shelf but wouldnt wildly oscillate. Others will give a large Jolt, and some have waves with oscillations, but arent as often at all, at least not here. That is why, in day to day use areas, we do not put foam between our plates or drinking glasses in the cupboard. It IS recommended practice to have the kitchen cabinet doors have a latch, to keep the drinking glasses from "walking" off the shelves in a usual shake. Yes, a BIG ONE will knock the glasses against each other to break them all, but you would be surprised, there isnt much, if any,-- in the common quakes -- drinking glass breakage from knocking together. But, hmm. maybe hanging from the top as opposed to sitting on a shelf might mean the jars wouldnt move together -- my physics brain is getting fuzzy...
I absolutely agree that main storage is in boxes, and as much thought as is practicable on falling.... But, we do put jars out of the boxes in a day to day pantry area to grab easily for cooking, and refill this area from boxes when it gets low