Sadly, it doesn't seem possible to proceed.  I tried a few different NICs connected externally via thunderbolt (including a dual X540 and Thunderbolt enclosure that I use on most of my 2013 Mac Pro's) and USB to try to get past the no NIC detected screen, but I get pf exception 14 in world 2097152 with any of them connected.  I even tried 6.7U1 despite the fact it can't boot automatically on 2013 Mac Pro or older Mac Mini.

It is certainly possible but el Reg is talking about turning off signing enforcement in the boot security utility, which seems to work on 2018 Mac Mini since otherwise I don't think the ESXi kernel would start coming up at all.  I think this PSoD is storage or PCIe related for a few reasons.  First, I had PSoD problems on Mac Pro 2013 when trying to boot with a Thunderbolt-attached Optane 905 (just having it attached caused PSoD during boot).  Removing the internal m.sata from the 2013 Mac Pro allowed it to boot past that PSoD to interact with the Optane.  I did not keep the error message from that experiment, so I can't say it was the same PSoD.  Second, I see this PSoD effectively instantly after I see the ACPI initialization message on the ESXi yellow boot screen.  Third, ESXi 6.7u1 is almost completely broken on 2013 Mac Pro, but I discovered it will boot if you remove external devices - such as a thunderbolt attached dual 10Gbe NIC.  This same problem with booting 6.7u1 exists even on the ancient 2014 Mac Mini that does not have the T.2 or m.sata, so all of this sort points to ESXi 6.7 and 6.7u1 having a bad interaction with Apple's more recent firmware and PCIe and storage devices.

Yeah I'd like to see some detail on their configuration in terms of what they are using for USB storage and which USB NIC they got ESXi to boot and install on the 10Gbe model.  I was trying to get this working with the 6-core/64GB/10Gbe configuration of the 2018 Mac Mini and their screenshot shows the i3, though I'm not sure that would make much of a difference.  I did not try building an installer with the USB NIC VIB so I'll clearly need to work that before I try again, for some reason I thought the USB driver you flagged on your blog was baked in now.  Thinking back on it, I'm wondering if my PSoD problems were when I had devices connected via the thunderbolt/USB-C ports, since I tried both thunderbolt and USB NICs.  Maybe if I pile everything into the older USB ports and leave the Thunderbolt/USB-C ports bare I'll have a bit more luck.