When I set up a reading plan for a non-Bible book, e.g. Communion With God, it doesn't divide the book by pages, but only by chapters. See screenshot. There's no way to choose the divisions.
Jimmy,
this ill depend on whether the book you are reading has a page number index or not - if it's this Vyrso edition https://vyrso.com/product/14385/communion-with-the-triune-god , then it probably won't have any page numbers hat Logos could use to auto-divide the reading plan. In many instances, that would actually be a good thing.
Unfortunately there's no functionality to move the auto-generated breaks to more suitable positions. It may be possible to say "in 366 session" and Logos selects smaller chunks, but I don't own the resource to test that. If this doesn't work, and you are eager to have the plan conform to your wishes, you may end up with building a custom plan from selected portions of the book, which is a lot of manual work but should be feasible.
Mick