The rule book states for events 411, 412, 413, and 414:
13. Time Limits
13.1.The contestant has two (2) minutes to start his/her engine
and become airborne. If after two (2) minutes the contestant is
unable to start the engine, they will move to the end of the
round rotation. If the contestant fails to start a second time,
they shall receive zero for the round.
13.2. The contestant has one (1) minute from the time the
wheels leave the ground during takeoff to enter the aerobatic
box.13.3. There shall be no time limit while in the aerobatic box.
13.4. The contestant has two (2) minutes between leaving the
aerobatic box and touchdown for landing, unless required to
hold upon command from the appropriate official.
13.5. Prior to entering the aerobatic box, pilots shall be allowed
to perform appropriate trim and positioning maneuvers. Such
maneuvers may not be performed at low altitude or directly in
front of the judges. No aerobatics are allowed immediately
following the airplane breaking ground (except for freestyle).
Upon exiting the box pilots are allowed only the necessary
positioning maneuvers to execute a safe landing. No
unnecessary low altitude aerobatics are allowed. Any infraction
shall result in a penalty of zeroing the round.

There is nothing that states a time limit between sequences.