Requires:

{"or": [
  "canTrivialMidAirMorph",
  "h_useSpringBall",
  "canIBJ",
  {"and": [
    "Morph",
    "canCarefulJump"
  ]}
]},
{"obstaclesCleared": ["F"]}

Dev note: This base strat represents only backtracking after entering from 7. It is possible to avoid a mid-air morph by rolling off the platform above With HiJump, a full jump won't work, so the midair morph may not be very trivial.