12

Entrance condition:

"comeInWithGrappleSwing": {
  "blocks": [
    {"position": [13, 5], "environment": "water", "note": "Mt. Everest"},
    {"position": [7, 3], "note": "The Precious Room"},
    {"position": [7, 2], "note": "The Moat"},
    {"position": [8, 2], "note": "Bowling Alley"},
    {
      "position": [7, 3],
      "obstructions": [[6, 10]],
      "note": "Red Brinstar Firefleas Room"
    },
    {
      "position": [9, 2],
      "note": "Climb Supers Room, Bubble Mountain, Lava Grapple Tunnel"
    }
  ]
}

Requires:

"f_MaridiaTubeBroken",
"canTrickyGrappleJump"

Exit condition:

"leaveWithGrappleJump": {
  "position": "any"
}

Unlocks doors:

{"types": ["ammo"], "requires": []}

Dev note: Opening a Missile door while grapple jumping is tricky but possible.