other things not encapsulated in the parts list: My PC sits on the bottom shelf of a foodservice-style wire shelving rack. My motherboard's I/O shield is integrated and wasn't a perfect fit into the case.
The DP cable is, probably, in-spec. I usually buy Cable Matters or BlueRigger.
I do wonder if ferrite cores would help.
edit: The only similarity I notice in our builds is lower-end ASRock b650 motherboards.