In the other room, use at least 6 runway tiles to gain an extra run speed at least $1.D, with Speed Booster unequipped. Jump into a lateral mid-air morph and touch the door transition while descending close to the ground. Hold jump to do an uncontrolled bounce immediately after the transition. Pause as Samus passes under the first ceiling Grapple block. Equip Speed Booster and unequip Spring Ball, to get a spring fling. Pause again and re-equip Spring Ball to get a second spring fling.

Entrance condition:

{
  "comeInSpinning": {
    "speedBooster": "no",
    "unusableTiles": 3,
    "minExtraRunSpeed": "$1.D"
  }
}

Requires:

{
  "notable": "Spring Ball Bounce Left to Right"
}
"canInsaneJump"
"canSpeedyJump"
"canCrossRoomJumpIntoWater"
"canTrickySpringBallBounce"

Dev note: A comeInSpinning entrance condition is used to ensure it is possible to enter in the right position, even though technically Samus should enter morphed rather than spinning.