Hi X,
I am not from Laminar Research; just a flight simmer from downunder.
AMD CPUs and GPUs will work adequately with X-Plane but it is well known by serious flight simmers that NVidia GPUs and Intel CPU processors give a better performance than AMD components. If and when Vulkan is introduced into X-Plane then AMD components may provide an improved performance.
To confirm my comments have a look at some of the videos produced by Michael Brown from XforcePC whereby he compares AMD components. Michael's business specialises in building PCs suitable for X-Plane and does not use AMD products. Laminar Research recognises Michael's business as the only business in the USA for the supply of PCs suitable for X-Plane.
The link you need to look at and in particular the videos where Michael compares AMD components is found at https://www.youtube.com/user/col2mab/videos
If you are planning to build a purpose built unit then go for non-AMD.
Good luck
Glenn