To enter this room, you need to buffer a downright dash from the badeline hit, buffer a hyper, and downright dash again to slide on the floor.
After the downright dash in c-04, you must let go of right and only hold down until you clear the gap.

For the fast laser cycle, start the two left dashes when Madeline is under this pattern of the tiling.
Featherboost upright and cut near the spinners to not die.