I’m not ruling out MLUs for the current batch of J-20 frames, just saying it would be plausible that they don’t receive one. After all, we never saw this sort of upgrading process with J-10s and J-11s (except maybe now with potential J-11BGs). I think whether the current batch of J-20s do receive some retrofitting in the future largely depends on a number of factors:
1) Just how different will the next J-20 iteration be compared to today’s, and how modular are those changes, given that the next iteration is probably built on further improvements in China’s technological base.
2) Will there be spare production capacity of parts (especially engines) for an MLU
3) Does the budget for upgrading older J-20 frames make sense given that that same money could be used some other way to deliver the same or equal capabilities/force improvements, either through procurement of new frames for potential mid sized fighter, if one is inducted into the PLA), master turnover toward a next generation design, or perhaps something lateral like A2A capable UCAVs, etc.
There probably isn’t going to be a “final” version of the J-20. Rather they will probably continue to introduce new iterations, improvements, and variants over the lifespan of the design, at least so long as they follow a batch production process rather than a scale production process.
