Gigabyte has been busy building new BIOS's - they posted version F6h on their forums (BETA) for the AB350-GAMING-3
Looks like the memory compatibility is getting better - I'm able to run timings the RAM is rated for at 2666 MT/S with timings 15-17-17-17-34.
Notes: 2 x 16 GB Sticks (DUAL RANK) installed on the RED SLOTS (Patriot Dual Channel Kit - PC4-22400 - #PVE432G280C6KGY)
Was able to hit the it by performing the following
1) Left XMP Off
2) Set Memory Compatibilty Manually to - Disabled (note: enabling it makes the board use AGESA 1.0.0.0, not sure what AUTO picks)
3) Set Multiplier Manually to - 26
4) Set Memory Channel A Timings Manually to - 15-17-17-17-34
5) Set Memory Voltage to - 1.32 volts
(this is the only issue, my RAM is rated at 1.2 volts but in order for it not to do the boot loop, have to bump this up).
One thing I did notice on this new BIOS, it's now finally showing the proper COMMAND RATE (2T) and the CAS LATENCY isn't getting rounded up to an EVEN number anymore unlike the OLD BIOS (was forcing it to 1T, and CAS LATENCY always got rounded up to an even number, so setting 15 - it became 16). Gigabyte verified that this is running AGESA 1.0.0.4 (but they forgot to change the string from 1.0.0.3 which they'll fix the next round)