So I narrowed my freezing and weird boot up issues on my C6H, with the latest BIOS, down to memory.
I went and got timings from the Ryzen DRAM calculator and it fixed my problems. (I left my primary timings as XMP, then all the other subtimings from the DRAM calculator).
I believe the primary timing you should ALL be changing is TCKE. It is set to 0 by default, it should be 8. I believe this is what is causing all our problems.
Hope this helps someone!