Yeah, if both cards are exhibiting the same behavior, the build or configuration is probably the problem.
Yes, please test with all overclocking disabled including XMP.
I did a "Load optimized defaults", which removed all OC'ing including XMP.
I then printed out from your guide the exact BIOS changes to make and did those.
I then rebooted, and was able to reproduce the error again within minutes of starting gameplay.
The stack on both says somewhat similar things; on the other it's cpu0 but otherwise similar:
panic(cpu 6 caller 0xffffff8018c652fa): Kernel trap at 0xffffff7f9befce97, type 14=page fault, registers:
CR0: 0x000000008001003b, CR2: 0xffffff81def77004, CR3: 0x0000000024934000, CR4: 0x00000000003626e0
RAX: 0x0000000000000331, RBX: 0x0000000000000331, RCX: 0xffffff821227bcc4, RDX: 0x0000000000000340
RSP: 0xffffff821227bc78, RBP: 0xffffff821227bc80, RSI: 0xffffff81def76340, RDI: 0x0000000000000331
R8: 0x0000000000000001, R9: 0x0000000000000003, R10: 0x0000000000000000, R11: 0x0000000000000000
R12: 0xffffff821227bdd8, R13: 0xffffff8211008f48, R14: 0xffffff81def76340, R15: 0xffffff821227bde4
RFL: 0x0000000000010283, RIP: 0xffffff7f9befce97, CS: 0x0000000000000008, SS: 0x0000000000000010
Fault CR2: 0xffffff81def77004, Error code: 0x0000000000000000, Fault CPU: 0x6, PL: 0, VF: 1
Backtrace (CPU 6), Frame : Return Address
0xffffff821227b6d0 : 0xffffff8018b3bb2b mach_kernel : _handle_debugger_trap + 0x47b
0xffffff821227b720 : 0xffffff8018c734d5 mach_kernel : _kdp_i386_trap + 0x155
0xffffff821227b760 : 0xffffff8018c64f4e mach_kernel : _kernel_trap + 0x4ee
0xffffff821227b7b0 : 0xffffff8018ae2a40 mach_kernel : _return_from_trap + 0xe0
0xffffff821227b7d0 : 0xffffff8018b3b217 mach_kernel : _DebuggerTrapWithState + 0x17
0xffffff821227b8d0 : 0xffffff8018b3b5fb mach_kernel : _panic_trap_to_debugger + 0x21b
0xffffff821227b920 : 0xffffff80192d2aa9 mach_kernel : _panic + 0x61
0xffffff821227b990 : 0xffffff8018c652fa mach_kernel : _sync_iss_to_iks + 0x2aa
0xffffff821227bb10 : 0xffffff8018c64ff8 mach_kernel : _kernel_trap + 0x598
0xffffff821227bb60 : 0xffffff8018ae2a40 mach_kernel : _return_from_trap + 0xe0
0xffffff821227bb80 : 0xffffff7f9befce97 com.apple.kext.AMDRadeonX4000 : __ZN29AMDRadeonX4000_AMDVIPM4Engine21validateCommandBufferEPjjS0_ + 0x19
0xffffff821227bc80 : 0xffffff7f9be62df1 com.apple.kext.AMDRadeonX4000 : __ZN30AMDRadeonX4000_AMDAccelChannel38writePendingCommandInfoDiagnosisReportERPcRjP18AMD_COMMAND_BUFFERP11IOAccelTask + 0x1cd
0xffffff821227bcf0 : 0xffffff7f9be62bcb com.apple.kext.AMDRadeonX4000 : __ZN30AMDRadeonX4000_AMDAccelChannel20writeDiagnosisReportERPcRj + 0x715
0xffffff821227bd80 : 0xffffff7f9be5e40a com.apple.kext.AMDRadeonX4000 : __ZN37AMDRadeonX4000_AMDGraphicsAccelerator20writeDiagnosisReportERPcRj + 0x168
0xffffff821227bdc0 : 0xffffff7f9be62432 com.apple.kext.AMDRadeonX4000 : __ZN30AMDRadeonX4000_AMDAccelChannel26getHardwareDiagnosisReportEPj + 0x192
0xffffff821227be10 : 0xffffff7f9bc3f877 com.apple.iokit.IOAcceleratorFamily2 : __ZN19IOAccelFIFOChannel27restartEv + 0x10f
0xffffff821227be60 : 0xffffff7f9bc4d438 com.apple.iokit.IOAcceleratorFamily2 : __ZN20IOAccelEventMachine215restart_channelEv + 0xe8
0xffffff821227bea0 : 0xffffff7f9bc4cbf8 com.apple.iokit.IOAcceleratorFamily2 : __ZN20IOAccelEventMachine218hardwareErrorEventEv + 0x206
0xffffff821227bee0 : 0xffffff801924109d mach_kernel : __ZN22IOInterruptEventSource12checkForWorkEv + 0x17d
0xffffff821227bf30 : 0xffffff801923f9e2 mach_kernel : __ZN10IOWorkLoop15runEventSourcesEv + 0x192
0xffffff821227bf70 : 0xffffff801923ef6c mach_kernel : __ZN10IOWorkLoop10threadMainEv + 0x2c
0xffffff821227bfa0 : 0xffffff8018ae213e mach_kernel : _call_continuation + 0x2e
Kernel Extensions in backtrace:
com.apple.iokit.IOAcceleratorFamily2(438.3.1)[66992525-3204-3CB0-8F03-4B70031B1CF2]@0xffffff7f9bc3b000->0xffffff7f9bcfefff
dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[A243D030-19AC-30AA-AC70-6C786DF9E6CE]@0xffffff7f99bf7000
dependency: com.apple.iokit.IOPCIFamily(2.9)[ADD485B5-3EF8-37C4-B3C5-F86326E497A4]@0xffffff7f9952f000
dependency: com.apple.iokit.IOSurface(269.6)[42377B3B-D14A-368E-820F-07E7EA666198]@0xffffff7f9bc0a000
dependency: com.apple.iokit.IOGraphicsFamily(569.4)[1F9B5D88-52DB-3A16-8373-4F608A3CB2D8]@0xffffff7f99f18000
dependency: com.apple.iokit.IOReportFamily(47)[988360A2-2E10-3014-A119-BE81BC045A10]@0xffffff7f9992c000
com.apple.kext.AMDRadeonX4000(3.0.5)[5FD7AE5F-C03C-34A1-803F-ACA9B68524D0]@0xffffff7f9be58000->0xffffff7f9c39cfff
dependency: com.apple.iokit.IOPCIFamily(2.9)[ADD485B5-3EF8-37C4-B3C5-F86326E497A4]@0xffffff7f9952f000
dependency: com.apple.iokit.IOSurface(269.6)[42377B3B-D14A-368E-820F-07E7EA666198]@0xffffff7f9bc0a000
dependency: com.apple.iokit.IOGraphicsFamily(569.4)[1F9B5D88-52DB-3A16-8373-4F608A3CB2D8]@0xffffff7f99f18000
dependency: com.apple.iokit.IOAcceleratorFamily2(438.3.1)[66992525-3204-3CB0-8F03-4B70031B1CF2]@0xffffff7f9bc3b000
The other backtrace (from another crash this morning) is similar:
Kernel Extensions in backtrace:
com.apple.iokit.IOAcceleratorFamily2(438.3.1)[66992525-3204-3CB0-8F03-4B70031B1CF2]@0xffffff7f8ee3b000->0xffffff7f8eefefff
dependency: com.apple.driver.AppleMobileFileIntegrity(1.0.5)[A243D030-19AC-30AA-AC70-6C786DF9E6CE]@0xffffff7f8cdf7000
dependency: com.apple.iokit.IOPCIFamily(2.9)[ADD485B5-3EF8-37C4-B3C5-F86326E497A4]@0xffffff7f8c72f000
dependency: com.apple.iokit.IOSurface(269.6)[42377B3B-D14A-368E-820F-07E7EA666198]@0xffffff7f8ee0a000
dependency: com.apple.iokit.IOGraphicsFamily(569.4)[1F9B5D88-52DB-3A16-8373-4F608A3CB2D8]@0xffffff7f8d118000
dependency: com.apple.iokit.IOReportFamily(47)[988360A2-2E10-3014-A119-BE81BC045A10]@0xffffff7f8cb2c000
com.apple.kext.AMDRadeonX4000(3.0.5)[5FD7AE5F-C03C-34A1-803F-ACA9B68524D0]@0xffffff7f8f058000->0xffffff7f8f59cfff
dependency: com.apple.iokit.IOPCIFamily(2.9)[ADD485B5-3EF8-37C4-B3C5-F86326E497A4]@0xffffff7f8c72f000
dependency: com.apple.iokit.IOSurface(269.6)[42377B3B-D14A-368E-820F-07E7EA666198]@0xffffff7f8ee0a000
dependency: com.apple.iokit.IOGraphicsFamily(569.4)[1F9B5D88-52DB-3A16-8373-4F608A3CB2D8]@0xffffff7f8d118000
dependency: com.apple.iokit.IOAcceleratorFamily2(438.3.1)[66992525-3204-3CB0-8F03-4B70031B1CF2]@0xffffff7f8ee3b000
Without access to a debugger (windbg, anyone?) it's tough for me to do more with this, but I do note a panic file (memory dump describing the kernel memory at the time of the crash, hopefully) was written.