Yes, it occurred to me after posting that it's possible to use the Custom Review page, but that's not as convenient as the "Test" button, since it requires having to look up the first and last kanji of each chapter. Moreover, it does not work for every situation. For example, I'm using the old edition of RTK, and learning the supplement kanjis as I go along. There is currently no way to test myself on the 10 supplement kanji, nor on the 60 out of the 965 RTK kanji, that I've learned so far. (The "Review from known kanji" of "Custom Review" includes those kanji, but it's not very efficient.) I can't imagine that I'm the only one with this problem.
I've been using the Test option very productively. Removing it just because some people don't understand what it's for doesn't seem to me to be a good idea. Changing it so that it includes only the kanjis that are in the user's list, or at least adding a second button, titled something like "Test known kanji" to accomplish this, would be a relatively simple change and solve this problem.
I've been using the Test option very productively. Removing it just because some people don't understand what it's for doesn't seem to me to be a good idea. Changing it so that it includes only the kanjis that are in the user's list, or at least adding a second button, titled something like "Test known kanji" to accomplish this, would be a relatively simple change and solve this problem.