I am trying to say that a single engine 5th generation fighter will need a big engine like the F35. It is simply better to go with twin engines than with such a big engine. The plane will be more sleek and wider with 2 engines, thus giving is less RCS and higher wing area. Single engine 5th generation plane is a big no. F35 is a good example of failure to not repeat. F35 is aerodynamically very bad. Ideally, a plane of F35 size needed 250kN of thrust but due to single engine limitation, it got just 180kN. In addition, the wing area is small and the belly too big which makes it very poor in maneuverability. F22 on the other hand is an ideal example of excellent 5th generation plane. Even Su57, J20 are all twin engine planes for the same reason.
UTTAM AESA has been undergoing tests since 2016 and not yet complete because the project itself started in 2014. You can't expect a projet to complete by 4 years, especially for an AESA radar. The fact that these people completed the air-air code in 2 years and started shows a lot about quality of Indian scientists and coders. Even in EW pods, DRDO has access to materials from Israel and Russia where the right equipment can be inserted. The only thing not accessible is the coding. In this part, I have full faith in Indian coders. So, I consider EW as easily completable.
Tejas MK2 has been sanctioned in 2013 where Tejas Mk1 was rejected as deficient and a new project sanctioned (just like Arjun tank saga). It has completed its preliminary design review and even dimensions have been declared in a news article a few months back. The naval version was also sanctioned and Mr Lanba himself acknowledged that.
Cost analysis. Why we need SE fighters when TE fighters can be inducted. Its the costs. In not so long future we would be operating only 5th gen birds. 4th gen birds will be phased out and countries will look (India included) for cheap single engine 5th gen ac. U cant have premier 5th gen ac going to skies for small trifles like escorting or uninformed civilian plane or investigating an area. What I do talk makes sense. If someone is inducting an ac from 2030, its expected to serve till 2070, and it would be comical to see an 4th gen ac in 2070's. Moreover IAF knows more than us on what to decide.
Do u know Thales prepared and tested an new radar for mk1a programme in less than 6 months? Its based from an another model. But still 6 months. Cos they have prior experience. Same goes for our radar, EW suite etc. EW suite was integrated and flight tested on our Tejas in 2015. But not much progress have been made that we are now going back to the Israelis. Reason? Defence Electronics is another ballgame altogether. DRDO will get better with time.