Is this a firmware issue?

My computer recently developed an issue that is causing VERY long boot times into Mojave and causes Catalina to trigger a kernel panic while booting (resulting in an infinite loop).

I've reformatted the hard drive and done fresh installations of both Mojave and Catalina but the problem persists.

The specific issue that seems to be causing Mojave to slow way down on boot and Catalina to panic revolves around about 50 of these style messages:

[IGPU] Begin Gfx firmer load process

[IGPU] ForceWake Multithread = 0x80000000

[IGPU] CONFIG0 (0xD00) = 0x80000000

[IGPU] GT_THREAD_STATUS = 0x400b0000

[IGPU] Doing retry #49

[IGPU] Failed to wake the ME.

[IGPU] Failed to wake the ME

[IGPU] ForceWake Multithread = 0x80000000

[IGPU] CONFIG0 (0xD00) = 0x80000000

[IGPU] GT_THREAD_STATUS = 0x400b0000

[IGPU] Doing retry #49

After about 50 attempt Mojave finishes the boot and loads however if the computer falls asleep it will not wake up without being forcibly shut off. Catalina however triggers this message after 50 attempts:

[IGPU] Failed to wake the ME.

[IGPU] ---------------------------------------------------------------------------

[IGPU] We're going to panic with : [IGPU] Failed to wake the ME.

[IGPU] ---------------------------------------------------------------------------

Among other things I've also tried booting into Apple's hardware diagnostics mode but after the 2 min hardware test it found no issues (ADP000)

And just to double check I've also run ford aid on my HDD with no issues reported as well.

I even went as far as to manually rebuild the fusion drive thinking that maybe it got corrupted somehow (which also triggers a full wipe of the data) and the problem persists. At this point I've installed off of flash drives, and all 3 recovery modes (re-install current OS, reinstall factory OS, install latest OS) with all options resulting in the same behavior outlined above.

If the hardware is ok, and this many different attempts to install the OS on a freshly formatted hard drive all results in persistent problems am I correct in assuming a firmware issue? And if so is there any next steps to try? My understanding is that apple only make updates available for firmware as part of the software update process these days and does not offer a full copy for us to re-install ourselves.

Any ideas?