This box would be redundant - for the games based on quizzes, ALL quizzes are eligible except those way too specialized (you wouldn't see stuff about a specific episode of a TV show). If fact editors do have the opposite button to specifically exclude a specific question from consideration in case it does cause problems in the game.
For TvT and, increasingly, other games, we use the single questions which are inherently an ever-growing pool. With the daily challenges now involving writing these questions, we see quite good growth there, so more and more games will use that pool.
FT Editor and Administrator
Guardian of the Tower