That's all not a problem for prototype, the way Chinese pumping money to its R&D,copying, stealing etc will definitely will help them to rectify all those mentioned problems in a matter of time. I think we Indians are lagging too much in gen5 fighter development as AMCA still only a few computer generated pictures and indo-Russian fgfa program going nowhere.
To all my Indian friends who is trashing j20 & its capabilities based on some eyeball research, one thing you should remember that "under estimating your enemy is the biggest mistake you can do in your life". After all those Chinese are having two different active gen5 stealth fighter program,where we are having none.