So, I tried putting my drives in the USB 3 ports on the back per this post: Cannot install in UEFI mode: Buffer Too Small - #16 by FLVAL but still ran into the same thing.
I was able to edit the kernel parameters as you and joekamprad described but it went to the same “buffer too small” screen.
I tried looking through my memory options in BIOS but everything just looked to be about adjusting the timings on the DIMMs so left them as is. Potentially worth noting, though, is that inside of Advanced>USB configuration, the option to toggle Legacy USB Support seems to insist on being toggled on. Each time I’ve restarted and checked there, it is on despite experimenting with toggling it off (and yes, I’m saving settings each time before resetting).
I also loaded an ISO of arch on one of the drives and tossed that in the back. This, too, was able to get to that boot selector menu. My computer’s POST speaker starting beeping somewhat randomly including most times if I arrowed up or down in menu. I attempted to do the regular boot option which gave the buffer too small error. Then tried the default with nomodeset which gave the same.
Interestingly, though, if I run the default with that paranoia setting, Arch does actually boot!