this make no sense at all bro ..I think the J-31 platform would be better for future development than the J-20, there can be an EW focused version, and it could be possible to develop a BIGGER version, scaled up and designed for dual WS-15 engines, to take over the J-16 and J-16D roles, let’s call it a hypothetical J-36.
WS-19 is the final engine of J-35/J-31.. WS-19 is as good as WS-15.