The new practice page says "These are the vocab lists that words will be added from during practice." but the queue is not listed and it is a list that vocab is added from. It's not clear how often it's added from (I think it's just one of many lists, not always the first list to add from). Sometimes one might want to pause the queue but I don't know if you can do that from the active lists tab.
On a closely related note, I do like the "add word" / (+) button a lot. It is quite useful for letting me add a lot of words early in a long practice session (e.g. if I have several hundred items to review but want to make sure I add all the characters for my next class).