The final design has already been made with conformal weapon in mind. So I think it doesnt need to be redesigned. The plane is also bigger than F 35. This is a statement from person inside the program:
Google Translate from Korean.
An official of the development team said, "There is space to make space for internal armed windows and change all avionics equipment to conformal type." "Now we are developing and integrating each technology into the field of making the first full-scale fighter aircraft." . In order for the KF-X to have a stealth function, it must wait until the block 2, or block 3, is produced. However, no one can guarantee that we will be able to go to Block 2 and Block 3 at any time. The level of technology is also a matter of concern, but it has not been discussed at all in the mid to long term.
Here is the source:
[권홍우 선임기자의 무기이야기] KF-X는 4.5세대 전투기...스텔스기로 진화 가능성 길 열다
정치 > 정치일반 뉴스: 한국형 전투기(KF-X) 사업이 첫 관문을 넘었다. 기본설계를 마친 것이다. 앞으로 약 14개월 동안의 상세 설계 절차가 남았으나 ...www.sedaily.com
Another one:
To allow the jet to hold such equipment, KAI designed the KFX’s fuselage to resemble a stealth jet akin to Lockheed Martin’s F-22. Most of the sensors are located inside the aircraft, while the four air-to-air missiles installed on the KFX are half buried in the central part of the fuselage. Space was also left on the aircraft for the future installation of an internal weapons bay - a characteristic component of stealth fighters.
According to one KAI spokesperson, once the KFX’s stealth capacity is enhanced, it will be comparable to the F-117 - Lockheed Martin’s famed stealth attack aircraft that outclasses the F-35 in numerous ways.
Here is the source:
I am new to the KF-X. Where exactly the conformal weapon's bay is to be attached?
Do you think a conformal weapon's bay is as good as a designed-in internal weapon's bay?
I would still hazard a guess that it would be a trade-off in the stealth profile for the sake of the mission profile.
But that is my humble opinion.