I have also been researching OCC XLR cables, and I found a new manufacturer (to me, at least): Artic Cables, supposedly are "Handcrafted in Florida, USA".
FYI - From their website (below) it appears that they have invested in new OCC production equipment. Also on their website, they state
"Arctic produces the purest copper and silver OCC Litz wires on the market, which utilize some of the most complex Litz designs and deliver top-notch performance, comfort, and aesthetics."
From and email with them, I also learned:
It's 18AWG per conductor. The combined gauge is 13AWG per cable.
We use a cutting-edge manufacturing process to produce our wires.
Our testing samples reach a purity of approximately 99.99999N, which is considered the highest purity in the market.
I have no affiliation, just shopping for a better cable... Has anyone tried these cables or have anything else to add?