Thanks to =GT at CD
1) Is the spool time supposed to be that long?
2) Is that two elevators on the trailing edge I see?
It also just dawned on me that the J-20 doesn't need the WS-15s for peak flight test conditions so long as the plane's T:W (not the engine's, the plane's) matches specifications.
Also, the bobbing it does while on the runway seems to imply that the J-20 is very back heavy as it is right now.