This is a minor aesthetic problem. When I was doing the French tree, I took shortcut exams for some sections. For each shortcut exam of every section of the tree, there are 3 trials. If you fail all of them, the shortcut icon disappears and the section gets mixed with the next one; they blend together without separation. This is all well and good but I think even if you can't take the shortcut exam anymore, the tree sections should still be separated by some kind of icon just so you can keep track of your progress, know which sections that need strengthening, and so on.
Also, that very icon could be used in the future, after completing the section, for practicing all the words from that particular section en masse in a longer exam.
As I said it's a minor thing but if there's a quick, simple solution, I'd be so grateful. And if there are reasons as to why it should be kept the way it is, please let me know.