I would really like, using Mandarin as an example, a more thorough description of how things are organized in the course. For example I am working through the HSK 5 course right now, and I learned multiple bigrams which contained 1-2 new characters, before I learned the single characters. It would have been nice to know this before hand so I could have skipped to those levels and saved some learning time.
To expand on this, For courses with thousands of items it would be nice for the course creator to logically explain how they justified ordering things. Sometimes, I thought of organizing a course using semanto-phonetic characters so that way I could quickly learn the pinyin for a family of characters (which, for me is the hardest part of learning Chinese). But I currently have not found a course which does that, but it may exist and I just don’t know. This is because the descriptions for courses are often quite vague, or just lists.
Another thing I would be interested in seeing, is some sort of metric for how many people have been recently active in making edits to the course. Because this might imply that a course is not active, so if you find that there aren’t a good number of alternate meanings, it might be agitating to go through. Especially if these courses don’t “link up” with previous courses in the database. So the same word may have a slightly different meaning in this new course. These types of things I would like to see.