When walking up to the cutscene trigger near the beginning of Island intro that the camera stops panning to the right. It has been noted for a while now that pausing and unpausing the game in this state causes the camera to lock both horizontally and vertically near crash. You can continue to pause and unpause the game to move the camera for the rest of the level. As a result of this, you do not need to watch the cutscene, but pausing and unpausing is slower than just watching the cutscene.

It was previously believed that walking off-screen to the right when the camera was locked would trigger the cutscene, so this wasn't explored too in depth.

However, yesterday, I found that but bringing the camera near the cliff that needs to be double-jumped, walking off-screen does not cause the cutscene to play.

When off-screen the stage has loaded, but elements of the stage, such as boxes (event metal ones), and the tutorial marker have not spawned.

The stage is completable under these circumstances, although you do need to pause-unpause to load the portal, and watch out for the two pits present in the level, as since the camera is locked, you'd basically be doing the level blind.

For what little experimenting I've done, you need to pause the game three times to get the camera to a point where walking off-screen will not trigger the cutscene. What this comes down to is you can remove all obstacles for the level, such as having to jump over the metal boxes, avoiding the nitro, and getting passed the tutorial things, with the price being pausing the game three times and doing the level blind.

If this does save time, I doubt it would be much, 1-2 seconds at most, and if we could reduce the number of pauses down from three to two, that could be a save as high as 5 seconds.

I doubt that anyone will actually ever try this in a run, although it might be something to TAS people to look at (made a post over on TASVideos.org), and should definitely be noted as a thing that exists.

Here's a link to my video showing it off with an overlay made by Spikestuff and Warepire:

And here's a link to a quick video I recorded showing that it does indeed work on console:

Update:

One of the nice guys over at TASVideos.org (ThunderAxe31) was able to take a look into this glitch to see if there was any use. Unfortunately (or fortunately depending on how you look at it) not only is no time saved, but it is slower in tas, which almost certainly means that it will be slower in rta.