I have a few books in my library (primarily by Tom Wright) that are not lectionary-based, are not daily devotionals, and which don't really work if you try to set them up on reading plans. The main ones I am thinking of are the three Lent for Everyone and the three Twelve Months of Sundays books.
The Lent books have a daily reading for every day in Lent and Easter, but you have to know where you are in the cycle to pick up the right reading. I was slightly surprised that there's no way of reading them in Logos apart from simply using them like a monograph. It would be great if they were somehow set up to read as lectionaries.
The Sundays books have a reading for each Sunday in the liturgical year, but are also only indexed on page. It would be really great if there were a way in Logos of having these appear in the "Devotionals" section with the appropriate day offered for reading. This would also be a great value-add for buying these books in Logos, rather than K****e format. I don't know if they can be linked to any of the lectionary-based offerings that are coming out, but people like Wright do also have a strong following in the world of churches who don't use or observe the liturgical year so this sort of functionality would be of use to a lot of us outside that world.