The Split Kit signals the podcast players to do different things (e.g. chapters, value splits) while you're live podcasting. For instance, if you decide to play a song on the show, you can go into the splitkit, pull up the song, and it will tell the podcast players listening to switch to the wallet of that song.

It's only used for live podcasting and anything you do needs to be transferred over to the RSS feed once you publish the episode.