Dimension Skip

Dimension Skip or Hub 3 Skip is a major skip used in Any% 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. They 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 tried to use the Skew Glitch to clip from the Psychetron to the corridor.

A few days later, Bandicraft showed that the Cortex Floor Clip was indeed possible. After that, many runners tried to do this and the understanding of where Crash has to go and how to clip Cortex got better. Joester98 was the first person to do the skip without cheats.

Tutorials
Visualization of the area with the load wall and the cutscene trigger by Banned User.

Bring Cortex on the corridor
Throw Cortex, quickly climb, grab Cortex and trigger the load wall. You successfully went through 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. Nudging the movement stick right before he teleports might help.

Walk into Cortex
If Cortex is in the perfect position, walk just behind him. Otherwise, go more to the right or to the left so he stops against Cortex during the cutscene.

Hit the object
Hold the spin button (Square or X) and Up-Right with the joystick to go around Cortex and quickly hit the object. You may have to adapt your joystick angle depending on where Crash stops. If the Cortex you use comes from the 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. It isn't successful if Crash didn't twitch or if Crash teleported to the room.

Jump to the OoB load wall
Long jump. Visualization of the area with the load wall and the cutscene trigger by Banned User on Discord.