I had a chance to try this. It does work on both the iPad and macOS. The implementation is a tad funky. Previously you had a line drawn from box to box which was easy to follow, even if you skipped ahead several pages. This time each box gets a color coded number. Each sequence of linked boxes, a thread, has its own color. This is OK for a short document or a poster. I wonder about discovery of the other boxes in the thread as there is no visible line connecting them. If you click on the little bubble above the box you do get a list of numbers indicating how many boxes are in the thread. There may be more information here that I haven't discovered yet.
The new light table in Keynote looks nice. I can imagine this being quite useful.