He had a lot of intentional limitations. 32-bit, and did he support protected mode? I have a feeling it didn't but it's been a long time since I looked at TempleOS.

When VIA bought Cyrix (and the Intel ISA license) they tried to add a second execution path for their own architecture that never went anywhere. I think it was at Defcon where someone discovered it and learned they could switch between the two modes and get Ring0 access on the CPU from user space; and this was an embedded chip found in tons of old point-o-sales devices.

x86_64 is a steaming hot pile of "there be dragons" inside there.