I find it hilarious that you somehow can't find anything of value from f-16 forum, when actual pilots (Gums) and former F-16 engineers (johnwill) and F100 engineers (TEG) post there. Are there strong pro-US nationalistic sentiment there? Sure. But if you are somehow unable to parse and filter useful insights and dismiss everything on there as xenophobic then it's your own problem.
There is zero to be learned about Chinese aircraft there, or indeed any component or design used by Chinese aircraft that originates from Russia...due to the extremely xenophobic nature of the posters there. Any and all things Chinese or Russian are mocked and denigrated there as rubbish junk.
Who cares in the context of this CHINESE related forum ( I assume you are aware of the subject matter of this site) what past posters did on an F-16 previously at that toxic site? We are here to talk about CHINESE aircraft.
Why is that so hard for you to figure out?
Any information posted on that site regarding Chinese or Russian aircraft is basically rubbish that only serves to denigrate or put down. That is not "pro US nationalistic" as you have tried to explain it away..but deeply xenophobic with a racial tinge. It is infamous and notorious across the web for that for a good reason...and deservedly so.
If you are unable to see that..you need serious help.
Enough on the off topic or defending the indefensible already. This is about the Chinese J-20.