Hmmm, being labeled "that guy" is better than some of the things I've been called in this stream.
FBW is, for the most part, a generic technology that can be applied across different aircraft. In the west, you find Dassault's FBW informing both the Rafale and the Falcon family of business jets - which are incidentally produced on the same line. Embraer's FBW for the KC-390 benefits from its experience both with E-Jets, but also Airbus programmes.
If China is so brilliant at FBW - as everyone in the forum casually assumes - then why use external suppliers for high profile civilian programmes? Parker in the case of MA700, Honeywell with ARJ21 and C919. Sure, certification is one reason, but learning is another. Moreover, Civil-Military fusion is a high priority across all industries in China, aerospace foremost.
So, in the case of XAC, there will be significant learnings from working with Parker on FBW. Given that engineering personnel in aerospace outfits tend to work across a number of programs - especially given that MA700 is a dead duck owing to its lack of engines, so not much going on there - it is entirely reasonable to assume that there is some interplay between military/civilian programmes.
Let's flip this around. How can you categorically, definitively state there is absolutely no FBW interplay whatsoever between the MA700 and H-20 programmes? Do you work in the HR office at XAC? Are you part of the H-20 FBW design team?
No, the nature of this discussion puts the onus of providing evidence squarely on you. You are the one making the spectacular claim that is going against general common sense and challenges the null hypothesis here, so you are the one that has the make the evidence, and you don't have the right to demand others to prove a negative.
But I'll indulge you a little.
It is very obvious why a nation that previously has produced very few commercial aircraft may seek foreign companies with experience in commercial systems (with the requisite experience in certification/regulation, commercial maturity, and commercial commonality) to provide subsystems for a commercial aircraft. That's because the flight control system/FBW system (or indeed, any particular subsystem you want to think of) for a military aircraft -- regardless of how much more sophisticated it is compared to that of a commercial aircraft -- does not have to meet those same commercial criteria to try to achieve commercial success with minimal risk.
The logistical, certification, marketplace and customer requirements for a flying wing stealth bomber is massively different to a small or medium sized commercial passenger aircraft.
In essence, you are mistaking customer and marketplace requirements of commercial aircraft and equating it with wholesale technological advancement or capability, and your entire argument only makes sense based on that assumption.
I don't know why you've chosen this particular this hill to defend, but I commend your persistence.