When you look over the changes it seems like they want you to use 18 or above for some of the new features but that doesn't mean lower won't work. Maybe you want to look over the guides and see what some of the more experienced mods and members that wrote them recommend. I kind of like to follow my own path.
I think either rev 17 or rev 20, I'd go with 20. I also use CFG which seems more stable but apparently GX is good and looks nice but IN MY OPINION CFG is better, I don't have any probs with it at all, and I use one HDD on FAT32, and one as WBFS. Both work fine.
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