The ComingUp app (which is a fantastic feature I am very excited about) is only showing one group of lists. I have 4 groups of lists with 3-8 lists in each group, and only the lists from one group are showing up. I would love to help beta test a fix if that is helpful.
Additionally, I would say that the "My Day" smart list in ToDo would be a very handy, if not the most handy, thing to sync with this app. It's not the most straight-forward use, but it's how the app wants to show you the most relevant items (along with other smart lists like "Important"). So even though it's a slightly niche feature, it maps very closely to the items users would want to see on their watch.
Thanks!