Can't boot with RAM in Dual Channel Slots, MOBO problem? Ram out of QVL? Whole system slow?

I built my first working Hackintosh with a 8700K and a Z370 Aorus Gaming 5 board mid last year with the following parts:

PCPartPicker part list / Price breakdown by merchant

Everything works fine, even Wifi and hand-off with a Broadcom card, except one major thing impacting system performance:

It refuses to boot with my RAM in the correct configuration for dual channel mode.

After trying to boot with only one DIMM, It appears that DDR4_2 and DDR4_4 are not working, coming up with reserved post codes that lead me down a google search black hole of repeatedly reseating the CPU, ensuring the cooler is screwed on a equal number of turns on each screw and and checking for bent pins, even booting with one stick, disabling XMP and underclocking my memory, all to still receive a 4C post code that's reserved on the manual.

It could also be the case that because the exact SKU of my RAM isnt on the QVL for my Motherboard, but that's quite unlikely as the only difference with closest kit to mine included in the QVL is a different color heat spreader (ram timings and voltage are all the same), and it shows that 16GB DIMMS for that DIMM should work in every slot in dual channel.

Also unlikely is that I have a bad RAM kit. Both DIMMs do work, just only in DDR4_1 and DDR4_3, in single channel mode, which show up in High Sierra as the two rightmost slots out of a 2x2 grid.

So it appears pretty likely that it is the MOBO has blown a capacitor around a RAM socket or some other unfixable problem (I can't even RMA because I bought overseas from Newegg and they definitely won't refund me and My serial number sticker came off during a disassembly.)

I've had this problem since assembly and just haven't found a working solution after trying everything things that come up for the post codes that come up when I try to boot in this config.

I'm now considering one of 3 things: ordering a 4x16GB kit on the QVL to test if it is a compatibility issue, ordering another identical Ballistix kit to upgrade (and hope it magically works) or replacing the mobo altogether.

If I do need to replace my motherboard, what Z370 or (Z390 even?) board is a good replacement? Since the same model of motherboard, Z370 AORUS Gaming 5 is now out of stock in every brick and mortar store in my country and Amazon refuses to ship one to mt country from a third party vendor, My best course of action is looking for a replacement board with similar I/O, (Wifi slot, 2x M.2, at least 4x SATA, preferably even another Gigabyte board, as I have also got a Alpine Ridge TB3 card as a part of that build).

If I should change motherboards completely, it it still possible to avoid having to do a complete reinstall by booting from a Clover EFI on a installer USB stick tailored to a build centred around the new motherboard then copying it over like one would for a vanilla install?