I emailed SilencerCo about an 18x1 mount for the Octane, and here's what I got back:
Thank you for contacting us. At this time we are not making an 18x1 thread mount for the Octane. We are waiting to get a Scorpion Evo in from CZ so we can look into a mount for it. I will pass along your interest in an 18x1 Octane mount, and I have added you name and email to a file to notify you if we do make one. Please let me know if there is anything else we can help you with.
Have a great day.
I suppose I'll hold off on ordering an Octane, until they confirm they're making the mount.