As far as i understand the main problem with LSA is that through time oxidation occurs and there is loss of product, could that be stopped with an antioxidant?
I have one naturally occurring in mind, rosmarinic acid, it can be found in relatively high concentrations (8%) in extracts of the plant Rosmarinus officinalis.
My question here is if anyone is aware of any problems that may make this a bad idea or impossible.

LSA is itself a breakdown product of clavine alkaloids like Elymoclavine, LAH and Chanoclavine.

Oxygen, light and moisture (and heat) together work to cause this breakdown and using an antioxidant could potentially slow the rate of breakdown.

Decreasing exposure to light, air and moisture as well as heat can also go a long way to preserving alkaloid. Studies show that the breakdown begins to occur before the seed ripens and then proceeds until the clavines have become lysergic acid. This change also correlates to the seeds changing from a psychedelic to a sedative and is why fresh seeds produce better results.

Ageless oxygen absorber and silicon desiccant gel packs are also handy for preserving fragile psychedelic molecules.

Using the antioxidant is a good idea.
Rosmarinic acid might be worth a try.