Even though our traitorous 'State' Department gives our enemies advanced technology, unless one understands system level thinking, the only thing the Chinese will produce are targets.
This is not to discount the advances that can be made using US Government Cliff Notes. When Hughes Aerospace and Ron Brown (Commerce) gave away MIRV technology to the Chinese, they leap-frogged 40 years of experience and made the Chinese missiles a threat.
But vastly simpler missiles are not front line fighter aircraft.
The other thing we have going for us is that the Chinese are utterly corrupt. Besides copying designs from everyone, they counterfeit everything. They fake EVERYTHING. To meet PLA schedules I can envision sub-standard titanium/aluminum being used in critical stress areas (their supply chain will fake testing and certify it 'good')
I would not want to be Colonel Yang doing the maiden takeoff and landing on their refurbished Ukrainian carrier.
Even IF the Chinese manage to build a solid plane, it's got to be able to detect enemies without giving itself away, acquire the target without giving itself away and give and receive good intel without giving itself away. And they need the whole system including AWACS-type platforms.(All requiring world-class antennas and electronics the Chinese will have to develop.)
Not to discount their determination, or the Kenyan's ability to sell us out, but the Chinese can't steal everything. They will have to earn the top slot.
Now, th Chinese will benefit somewhat from our lessons, they will learn a few things from our own experiences and the published accounts of them. For example, they do not have to develop and angeld deck, optical landing systems, automated landing systems, color coded deck operations, etc. And they are studying everything we have written and documebnts (and we have open sourced a lot) about operations.
But their J-15 is a decent design. They have modernized the SU-33 and I believe even added an ASEA radar. They just haven't produced but six prototypes so far.
But they are producing decent J-11Bs now, and they may have solved their long standing indegenous engine problem. We shall see. They have literally hundreds and hundreds of SU-27s, SU-30s, J-11s, and now J-11Bs and train regularly wioth them because they have the finds...most of which are coming courtesy of us.
As to AWACS, they have them, purchased and them built foremr Russian designs (again) and in some numbers.