Enter with G-mode direct, and go to the top of the room to perform a Crystal Flash to refill on energy without destroying all the bottom Rinkas. Use the Rinkas to damage down. For the final hit that will trigger auto-reserves, stand in the open doorway between 1 and 6 pixels from the transition. The auto reserve trigger will cancel G-mode and close the door on top of Samus. Climb up 2 screens, moving quickly to minimize Rinka damage. Perform a turnaround buffered spin-jump away from the door to trigger the transition, bypassing any lock on the door.