Run from the adjacent room and jump at the end of the platform. Aim down just before bonking the ceiling.

This requires a last-frame jump and has a 2-frame window for the aim-down.

Entrance condition:

{
  "comeInRunning": {
    "speedBooster": true,
    "minTiles": 36
  }
}

Requires:

"canInsaneJump"
{
  "or": [
    "canBeVeryPatient",
    {
      "thornHits": 5
    }
  ]
}
{
  "not": "f_DefeatedPhantoon"
}

Dev note: The 5 thornHits are for lenience since it is very difficult to get this first try.