Raptor does have 4 plumbed hard points for drop tanks. My question is though how much fuel are these J20 fuel tanks packing?
I would suggest they are at least as large as the 600 gal tanks the Raptor carries, so between the 4 tanks 2400 to 2800 US Gals, not sure how that would translate?, that's a lot of fuel if you are high and the power is pulled back for loiter, if you go into full burner, it disappears in a surprising rush...
Depending on your life view? "speed is life" or "speed kills", LOL or we could just state the obvious and say "speed costs!" Ha Ha.
I doubt there is enough tanking in China to fly the missions they will be wanting to fly, so those "drop tanks" are indispensable.