In fact, there was both a hardware x86 emulation card, named "Hard PC", as well as a port of the relatively well-known SoftPC software emulator. Unfortunately, I have next to no information on the former; a quick search throws up the link below, which is interesting, but doesn't reveal anything too informative about the hardware.
I'm not at all sure if the PC-DOS button on the blue screen was the only way to boot this Hard PC hardware, or whether it could be accessed concurrently via CLIX. I do know that there was an InterPro model 29xx system designed and manufactured which was based on the 2xxx series case/monitor etc., but used a PC (Pentium?) motherboard, but this system was not able to run CLIX or CLIPPER software. It was basically just a PC in an InterPro box, designed to run Windows NT, supposed to allow existing customers to extend the life of their InterPro monitors and maybe some other peripherals.
The Hard PC board would be an excellent longer term emulation target, but I suspect there's even less information available than the slim pickings I have for the InterPro, so progress may be very slow.
Just found a few more bits and pieces of information - it appears the Hard PC had a 486 CPU, some kind of VGA hardware/emulation, and supported 2, 4, 8 or 16 megabytes of its own SIMM memory. It appears the board's "ROMs" (presumably system BIOS and VGA BIOS, at least) were loaded at start by the host, so it's possible these files exist somewhere in the OS media. I think the VGA on the board was essentially "copied" to the host video memory at runtime. All of these seems to indicate that the host and emulator could run concurrently.
PS: got enough SCSI working to enable the "rebuild" process to complete, and it's now crashing somewhere when attempting to boot the minimal rebuild environment.Old Microsoft knowledge base article relating to Intergraph HardPC