I believe they require right offset/helical...

I was worried they'd spin too much and cause fletch contact with the bow. Nick posted they'll spin an arrow twice in th first 5 feet. Should be great for stability, and I assume one could fine tune the nock to account for the spin so the fletch is lined up right as it passes the bow...

They aren't in production yet, having issues with the moulds last I heard a few weeks ago.