I think at this point what we need to understand is that, TurAF nor the potential adversaries will evaluate KAAN's capability on its exact RCS value compare to its peers. (Like F-35 or F-22)
There are three level of war-fighting in any domain.
*Tactical
*operational
*strategic
The only 5th gen fighter to probably fight as pure tactical platform is F-22.
But now thanks to rapid advance in drone, AI and future technologies, the characters of areal warfare are changing rapidly.
in tomorrow’s war fighting domain, a group of 5th gen and 6th gen fighters are increasingly becoming a part of highly automated network-centric (almost) OPERATIONAL LEVEL capabilities rather than a stand-alone tactical systems.
Similarly, KAAN will be developed into a System of Systems and then she herself will be a critical part of a larger puzzle in TurAF joint strategy.
It is no-brainer that, TurAF has set every requirement for KAAN after Comprehensive study and analysis of its future need to successfully deliver/implement its grand strategy in Tomorrow’s dynamic battlefield.
So, in my opinion, if the requirements set by TurAF for KAAN are met/exceeded, (including RCS value) then we should not obsess ourselves too much with the individual characteristics of the aircraft.