Question about Sony UBP-X800M2

I don't know the answer, but logically no.

Hello, unfortunately I don't have a region A Blue-Ray in my possession to test and I can't answer your question.
If I look at the technical specifications, this player is not "region free". Only ULTRA HD Blue-Rays are region free and playable regardless of their region of origin. It is therefore without having been able to test and by reading the technical specifications that I can tell you that this player is not "region free" and would require a hardware modification (soldering), software solutions not currently existing.