Crosshair VII Hero (WiFi) PCI woes, PCI-E reporting 1x (RESOLVED)

This is my first post so bear with me, but I hope to help someone else avoid the same headache.

I have looked EVERYWHERE to resolve my issues and eventually stumbled upon the solutions through trial and error. (ASUS support was WOEFULLY inadequate)

The Build:

• 1 x ASUS ROG Crosshair VII Hero (Wi-Fi) AM4 AMD X470 SATA 6Gb/s USB 3.1 ATX AMD Motherboard
• 1 x Cooler Master MasterLiquid ML240R Addressable RGB AIO CPU Liquid Cooler
• 1 x G.SKILL TridentZ RGB Series 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 2933 (PC4 23400)
• 1 x AMD RYZEN 7 2700X 8-Core 3.7 GHz (4.3 GHz Max Boost) Socket AM4 105W YD270XBGAFBOX
• 1 x Cooler Master V1200 - Fully Modular 1200W 80 PLUS Platinum PSU
• 2 x MSI Radeon R9 390X DirectX 12 R9 390X GAMING 8G 8GB 512-Bit
• 1 x Logitech G910 Orion Spark RGB Mechanical Gaming Keyboard
• 2 x WD Black 3TB Hard Disk Drive - 7200 RPM SATA 6Gb/s 64MB Cache 3.5 Inch - WD3003FZEX
• 2 x Crucial BX100 500GB SATA 2.5 inch Internal Solid State Drive (SSD) CT500BX100SSD1
• 1 x Cooler Master Cosmos II - Ultra Tower Computer Case with Metal Body and Hinged Side Panels
• 1 x M.M.O. 7 Adjustable Gaming Mouse

The Issues:

Prior to BIOS v. 0601:

• Long delays in explorer activities (creating folders, files, enumerating favorites)
• Periodic hangs when playing or browsing
• Screen periodically goes black for ~30 seconds and then recovers
• BSOD
• Memory won't run at XMP speeds
• Occasionally hard hangs requiring a forced reboot

Post BIOS v. 0601:

• Occasional long delays in explorer activities (creating folders, files, enumerating favorites; less predictable, but still present)
• Periodic hangs when browsing (I suspect it has to do with the explorer issue)
• Screen periodically goes black for ~30 seconds and then recovers several times (usually after a cold boot)
• PCI enumeration stuck at 8x,1x (Crossfire no longer functions)

The Fix:

• Manually tune the memory - the XMP settings were not applying correctly for me
• Disable Gear Down Mode and Bank Group Swap (these were causing BAD cache misses and buffer flushes in volatile apps like Chrome and Edge)
• In the Extreme Tweaker -> PCIE config, there are 3 tests, 2 of them are disabled by default but BIOS 0601 sets them to Auto. Disable tests 1 and 2. PCI config will immediately correct to 8x, 8x and Crossfire will work again.

I hope this saves someone else from an unnecessary RMA and allows them to enjoy the glory of their build.