Dimension Skip

Dimension Skip or Hub 3 Skip is a major skip allowing to go from Iceberg Lab to the 10th dimension lab, entirely skipping six levels. The skip works by going through the OoB load wall linking to the 10th dimension lab used by the cutscene after Hub 3. A specific flag set by cutscenes is needed for the hug cutscene to play when entering the 10th dimension, and this cutscene is needed to not be stuck underground.

History
In August of 2018, Gpro found that the hug cutscene plays in the 10th dimension lab after triggering the first Psychetron cutscene from out of bounds with the levitation cheat. Gpro thought that if Cortex could block Crash's path during the cutscene like the wall did with cheats it may as well keep that cutscene flag. A few days later, Gpro showed that indeed Cortex could be used to get the flag, but there was no known way to get Cortex there without cheats. A few days later, Bandicraft made a video explaining how they think it works and exposing five ideas. Some ideas didn't allow Crash to touch the area that gives the flag (using a Crash+Cortex Clip, blocking Crash with Cortex at the start of the cutscene trigger) and some ideas weren't done successfully (clipping from the psychetron to the corridor, using a Cortex Floor Clip). The next day, Gpro

Bring Cortex on the corridor
Throw Cortex, climb, grab Cortex and trigger the entrance load wall. You sucessfully triggered the load wall when you can see the Psychetron. Throw Cortex and jump over the door and the cutscene trigger.

Clip Cortex
Throw location and angle matter. Nudge the movement stick right before he teleports.

Walk into Cortex
If Cortex is in the perfect position, walk just behind him. If he's too much to the right, walk just behind him but a feet to the left. If he's too much to the left,

Hit the object
Hold the spin button (Square or X) and Up-Left with the joystick to go around Cortex and quickly hit the object.

You have to adapt your joystick angle depending on where Crash stops. If he stops behind but to the left of Cortex it means the setup was good and you have to hold Up-Left If you had to make him stop to the right because the clip wasn't good, hold Up-Right. If he stops right behind Cortex, you didn't position yourself right before going to the cutscene. You can try to hold a lot more to the left. If he didn't stop behind Cortex your setup wasn't good. If the Cortex you use comes from saljkdaj(Ice Climb route) and not from the farm, you don't have to go around Cortex. Just hold the spin button and Up.

It should be successful if Crash twitches and you have full control.

Jump to the OoB load wall
Long jump

Cortex is left in the first chunk
If Cortex was left in the hub chunk and you went in the Psychetron chunk (using the load wall), you can't interact with him. Death abuse or load the 1st chunk by going outside near the airship path and come back. https://youtu.be/b-ZvqTO1PCw?t=454

Crash fell
If you are still in the 1st chunk, you can go through the corridor wall https://youtu.be/b-ZvqTO1PCw?t=553 If you are in the 2nd chunk you can clip using a bodyslam You can always just death abuse as well.

The door opened, blocking the path
You can carefuly jump around the door https://youtu.be/b-ZvqTO1PCw?t=695

Triggering the cutscene early
If you missed your jump over the cutscene, you'll have to watch it and death abuse to retry.

Crash is not behind Cortex after the cutscene
Cortex positioning or Crash positioning before the cutscene weren't right.

Crash didn't move when I hold the direction
This means that Crash positioning before the cutscene wasn't right or that you don't hold enough to the left (or right). Make sure to hold the spin button as well.

Crash did move but didn't do the spin
This means you didn't hit the object. The object disappears quickly after you gain control, meaning that you weren't fast enough or that Cortex wasn't in the right position.