Unschooling allows free use of any and all bits of information, not just school's small set. A grid based first on cartoon characters or the history of ice skating can be expanded just as well as one built on a second-grade version of the discovery of North America and the made-up characters in some beginning-reader series. If the goal is to know everything, and if each person's internal "universe" is unique, then the order in which the information is acquired isn't as important as the ease and joy with which it is absorbed.
The time will come in your unschooling when you will forget to use checklists, but it won't matter. The child's internal grid will already have given them the need to know what things feel, smell and taste, and what they used to be or will be, and whether it's different in other places. Connections will continue to be made throughout their lives. The universe inside will grow larger and the universe outside will become clearer with every new experience.
Disposable Checklists
photo by Cass Kotrba