The main function of this randomizer is shuffling all the item locations. That means it’s completely possible to collect a spirit light container but get the double jump skill instead. Likewise, Skill Trees don’t always give you a skill, so you might find a Gorlek Ore when activating the Bash Skill Tree.
The item placement however is not completely random: there is an algorithm or logic to the chaos. This ensures that every playthrough is beatable by placing each progression item at a location you will be able to reach. For more information, you can read the paths sections of the seed generation. This mod also adds other functionality to the game. Click on the links below to learn more about them.