KF-21's AESA radar is a Galium nitride radar developed by HANWHA SYSTEM in South Korea with technology that started with the marine radar. The connection with Israel's Elta EL/M-2052 is that it was mounted on the Boeing 737's radar dome in combination with the EL/M-2052's back end for AESA radar test. South Korea didn't have its own AESA radar test system, so we only tested it with the help of Israel Elta. If you have the ability to understand technical data even at a basic level, you can see that EL/M-2052 and KF-21 AESA radar have no technical connection at all. However, you don't have that ability.
Korea is pretty smart, but the future success of the KF21 in international arms market will depend on pricing and product support. CCP China's failure in selling its various fighters lies not just in poor quality of its weapons, but also completely crappy customer support (basically Temu). Buying crappy weapons like the MIC (made in China) ends up being MORE expensive in the long run, because though they may be cheaper, they don't well and malfunction quickly, so you end up spending more money REPLACING them (and god forbid you get into a real war and the MICs cause you to lose). I really don't think that KF51 will be all that cheap when everything is added in (unless the Korean government subsidizes it significantly (and perhaps secretly, like the CCP with its electric car companies)). T he Koreans are certainly pretty astute to go after the potential market space of the NEW 4.0/4.5 fighter for countries that can't afford or be allowed to buy the only 5th generation fighter available for sale so far (F35, which a dozen US allies have bought). China doesn't export its J20 (so nobody really knows how good or bad it is), and its copy of the F35 (J31/35) has been in development for a dozen years without entering service (does that mean it's a very mediocre copy?); Russia can't even afford to buy its own Su57 (assuming you count it as a 5th gen aircraft), let alone export it (India already said No and dropped out of the program after being conned out of several billion dollars). The Su75 concept is dead before arrival, and I predict that it will be aborted. So, assuming that Korea can get some countries that don't have a huge military budget and can't buy the F35 (too expensive or the US doesn't allow it), they may get enough funding to further develop the KF21 into something closer to a true 5th generation fighter in the next 10-15 years. .It's something of a gamble,
South Korea upheld One China policy against Taiwan and South Korea needs China Gov as a dialogue channel to North Korea as only down to earth way to go. Taiwan does not any value for South Korea at all.