I posted on this too.
I have a lead on a USP Class VI Resin. I reached out to DSM on their Somos BioClear USP Class VI Resin.
This Resin provides FDA documentation. The only issue is the smallest quantity they sell is 10kg.
I reached out to DSM about getting 1kg quantity. They are looking into offering smaller quantities.
Another option is DSM Somos® WaterClear Ultra 10122 is the same resin but not FDA certified.