There are a lot of bug fixes and optimizations in Valve's latest steam deck update. The maximum length of a boot sequence has been increased from 10 seconds to 30 seconds.

Rock Paper Shotgun reports that some users were able to create their own sequence prior to native support.

Whatever this is.

Valve made the process easier to do in a separate update for the steam deck handheld, rather than attempting to shut down this tinkering. There is an online library where creators are posting videos for steam deck users to download, with a handful of 30-second-long sequences already available to use.

The easiest way to try it out is to create a folder pathway on the steam deck where the console will automatically look for video files to start. If you want to find videos directly from the source, then you may not have to wait long, as a data miner uncovered a document that suggests Valve is planning to sell its own movies on the steam store.

The testing features in the steam deck and preview channels are the only places where the long video sequence update can be found. There is no official release date for the public build, but you can test it out by going to the Steam Update Channel on the steam deck console.