It's possible to get into the passage by a non-mockball mid-air morph. It just needs to be fairly late. The Boyon will then push Samus into the passage.

Requires:

"Morph"
"canNeutralDamageBoost"
{
  "enemyDamage": {
    "enemy": "Boyon",
    "type": "contact",
    "hits": 1
  }
}
{
  "heatFrames": 350
}