I was pulling my hair out for ~6 hours trying to figure out why I kept getting the Apple circle with a strikethrough logo upon booting into the Mac OS Install from Clover.... It was driving me NUTS. I followed the entire guide for hours, retraced my steps, and after reformatting the damn flash drive over and over again, the problem ended up being the fact that I was using a USB 3.0 flash drive in a USB 3.0 slot. I moved the stick to another port and BAM! Everything started working. Currently 6:20AM but Hackintosh is finally UP AND RUNNING.
Mojave with Gigabyte X299 + i9-7920X + 1080Ti.
Thank you for your help!
EDIT: This is great and all, until you realize there is no hardware acceleration support on Mojave for series 8/9/10 cards. This would destroy Final Cut Pro productivity. Might have to downgrade to High Sierra until the web drivers are released.