That's an interesting approach for dice, and one I had not seen before. It is essentially the same basis as the Von Neumann debiasing algorithm for coins I linked to earlier in the thread, where you flip twice and discard the result if the two flips are the same, but adapted for dice.
Having said that, it's also far more complicated. I like to keep things simple and would just stick to coin flips.
Relevant discussion thread,
https://bitcointalk.org/index.php?topic=5440916.0. Anyway, i also agree Codex32 is rather complicated.
I saw Andrew Poelstra talking about this on a "Bitcoin Layer" podcast recently. I have casino grade dice, with the sharp edges. Are these really biased? I assumed the casinos would demand some controls during manufacturing to try un-bias the dice.
Unless you're an expert, there's no way you could know whether the company actually create dice with casino grade / reduced biased. It's not rare occurrence for company to exaggerate or even lying about their product standard/capability.