if you have a chance, try it. select a challenge but don't unselect it to complete it. Play a match and notice that any progress you make during the match is reverted after it. Meaning you can put a challenge that gives you points, like glyphs or plants. As long as you cont complete it in the archives by unselecting it, you can repeat it as many times as you want. It will go away after you close the game tho, because it will count the challenge as completed