There's no extractor cut on the 527 breech. It just has a shallow counterbore that's easy to copy with the take-off in hand. I've done a couple of them now in .223, 6 ARC, and .300 B/O. The only potential hangup is they're metric threads.From people at Savage and Howa that I've spoken to, Savage plans on a 6 ARC and Howa plans on releasing one as well. Ruger is utterly uninterested at the moment. That's too bad, as they likely would have the most affordable offering for use as a beater/truck/varmint gun.
A CZ can be "easily" converted if you're comfortable clocking a barrel and making extractor cuts. Having a smith retrofit a gun would likely be rather expensive compared to the cost of the gun itself, so from a cost standpoint, waiting may be in your best interest as the factory option would be much cheaper than buying a used 6.5G or 7.62x39 to do a caliber swap.