I keep thinking about making random A-Z quizzes, but as it is you would need to make groups of 26, and each alphabet group would always be the same. It'd be nice if you could make it so that instead of choosing x groups, it chooses x from each group. So if you found 5 alphabets worth of answers, instead of 5 possible quizzes, you'd have (I think) 26C5 quizzes, or 26,000+. Maybe call it something like random selections (from groups), not sure
And to go even further, being able to manually move group boundaries so you could have groups of different sizes, but that would need new UI stuff (you could have a menu within the random one that asks how many groups, then asks for how many members for each group, or in step 2 options to add/remove groups or group boundaries
Also, is there a reason there's no random click quiz option?