I mean you can call them "prototypes" or "initial production batch aircraft"
Well the currently flying aircraft should definitely be called "prototypes" because "initial production batch aircraft" is for after the development is finished, the design is finalized, and the aircraft is being produced for induction in the PLAAF, not for testing. The J-36 is clearly in its development phase not in its initial production phase.
but each modification is not necessarily on the same test aircraft, and just observing the paint by numbers is not reliable.
I put double quotes about "fooling". It is just an act that makes us military fans feel unhappy. The PLA should mark these "prototypes" or "non-prototype" improvements accurately and orderly, just like a military parade, instead of repainting numbers like 2004 on them for some "Worthless" purpose.
I am not sure what you are trying to say here. There could indeed be more than 1 flying prototype but are you suggesting that there are multiple different flying prototypes simultaneously given the same serial number? This seems highly unlikely, what is the benefit of doing this? Not only is this needlessly confusing for the people working on the plane but it is unnecessary. Serial numbers are just a number, why would they do this?
If calculated according to IOC, some of these "initial production batch aircraft" with huge modifications can be considered "prototypes", or they can be considered not prototypes. It depends on what we say, and has nothing to do with PLA or Chengfei
I have no idea what you are trying to say here. I believe IOC means "Initial Operational Capability" which is achieved after development is completed and the aircraft is being produced for actual PLAAF service. Perhaps you mean something different with IOC? Also again "initial production batch aircraft" are the first aircraft that are produced after development is complete and they are intended for actual PLAAF service.
Maybe you are misunderstanding or being overly optimistic about the timeline. The J-36 is not ready right now and it's not even close. If you think the first production J-36 for PLAAF front line use will come in 2025 you are way off on the timeline. We are not even close to that point it will take years more of development.