I've seen a similar project a while ago and thought this was about the same thing at first: [1][2]

Both essentially built a DIY chip tester for a 286 and both built around a Harris 80C286.

If I understood it correctly, the goal behind this project seems simulating the rest of the PC, purely for the challenge and learning experience, documenting the process of building the chip tester (and getting mildly philosophical in the process).

The other project was more directly interested in the 286 itself, undocumented instructions, corner cases in segmentation behavior, instruction cycle timing, etc. and also trying to find out if there are any difference between the Harris and Intel variants.

[1] https://forum.vcfed.org/index.php?threads/286-cpu-experiment...

[2] https://github.com/dbalsom/arduinoX86