Holy. That's an achievement very few people can claim. Wonder if HN has a "hall of fame", a worthy entry.

You did the smart thing there with the SoM (for the uninitiated: power sequencing to individual parts of an SoC and its external components is an epic hassle to get right and that's assuming you actually have proper documentation - without it it's an utter pain), but how in hell did you get the high frequency stuff working out on what was likely your first or second try? This is IMHO where your work really shines.

USB-C, DisplayPort (at 4K to boot) and PCIe at modern speeds are all but black magic to most, this isn't digital any more, this is good old analog circuitry and physics at work that most people don't even learn in university any more.