i'm using a public computer which cannot display chinese
i assume you are talking about launching with a normal wgf after ch df2?
this exists in t6 too, can be done when the opponent tries to ssr and attack but is countered by kazuya df2
this is because df2 has 2 frames of active hitbox, which are the 14th and the 15th frame, normally you can only hit people within the 14th frame, but if the opponent sidesteps to the right, with right timing he can dodge the 14f part and get hit by the 15f part, this will not change the recovery time for either side but will cause the opponent's whole recovery animation to start relatively 1 frame later, so kazuya will be able to move 14f prior to the opponent instead of 13f
by the way, you may have already realized this, that ewgf is not necessarily faster than wgf, the slowest ewgf is 42f, and the fastest wgf input is f,n,df,n+2, 14f no lightning, which requires extremely perfect timing and is even harder than a 13f ewgf