With only a runway length of 3 tiles (closed end) in the other room, this requires a precise setup: release forward for 3 or 4 frames, then repress forward on the last possible frame before the transition; alternatively, release forward for 2 frames and repress forward on the second-to-last possible frame before the transition.

If a longer runway is available (4 tiles), the timing windows are a bit more lenient: 1. Release forward for 3, 4, or 5 frames, repress forward on the last possible frame; 2. Release forward for 2 or 3 frames, repress forward on the 2nd-to-last possible frame; 3. Release forward for 1 or 2 frames, repress forward on the 3rd-to-last possible frame.

Entrance condition:

{
  "comeInStutterShinecharging": {
    "minTiles": 2.4375
  },
  "comesInHeated": "no"
}

Requires:

"canPreciseStutterWaterShineCharge"
{
  "or": [
    "Wave",
    "Spazer",
    "Plasma"
  ]
}
{
  "or": [
    {
      "and": [
        "h_enemyDrops",
        "h_underwaterCrystalSparkWithoutLenience"
      ]
    },
    "h_underwaterCrystalSpark"
  ]
}

Dev note: No lenience, because Power Bombs can be farmed from the Sciser. Killing it with Missiles or a Super is not represented, because it can not currently be multiplied by the lenience factor. FIXME: This is possible with a shorter runway, as low as 1 tile, but it's a lot worse. It would require more duplication and could be very tedious to set up for many attempts.