I wouldn't be surprised if the J-31 came in both high and low export variants, depending on the needs of the end-user.
One BIG advantage the J-31 has over the F-35 is that it uses twin medium-thrust engines, as opposed to a single high-thrust engine. As I was about to mention in the aerodynamics thread, one big advantage of smaller engines or sub-sized engines is that they need relatively lower materials tolerances than larger engines, because the amount of pressure per square inch at a given specific heat is lower. This means that smaller engines are easier to make to high tolerances than larger engines, just as an ant can lift many times its own weight, while an elephant can barely get itself locomotive.
Take the Eurojet engines used in the Eurofighter, for instance. Their initial variants were targeted at ~80kn of thrust, while their upgraded Ej2x0 variants are targeted at 100kn of thrust. The terminal plans for rthe Ej2x0 engines involve engines with something around 130kn of thrust each, suggesting a 13:1 T/W on the Eurojets, which surpasses the thrust to weight ratio on any other jet engine.
Now, for all we know, the F-35 will eventually have 240kn engines, because American and British engine technology is about a generation ahead of everyone else, but for what it has right now, it has a measly 190kn thrust engine that gives it about a .86 T/W ratio at best. With 230kn engines, though, it would be have a thrust to weight ratio more competitive to the Raptor, and might end up being capable of decent supersonic supercruise, helping to alleviate its BVR deficiencies.
However, for the J-31, we know that the RD-93 exists at between 80 and 95kn thrust, that the WS-13A is designed for 100kn thrust, and that there is a next-generation WS-17 project intended towards the late 2010s early 2020s time frame. What would the total thrust be on the WS-17? A reasonable guess would be around 120kn, giving the J-31 a total thrust of 240kn, and giving it a thrust to weight ratio above unity if it were to weigh around the same as a F-35.
Besides that, if the J-31 is intended as a carrier fighter, it'll be able to come out much later than the J-20, so it can be designed around the WS-17.
