[Harlowe] Multiple saves in the same passage

(set: $test to 1)
[save 1]<1|
[save 2]<2|
(click: ?1)[(set: $test to it+1)(save-game: "slot 1")]
(click: ?2)[(set: $test to it+1)(save-game: "slot 2")]

Why doesn't this work? This code creates three save slots, but if you inspect localStorage you see that the updated variable is not saved. Each slot saves the state of the variable when the passage was first printed, not at the moment the save-game macro is run. So, apparently, Harlowe needs a passage change to store new values into a savegame.

Is there any way of making this kind of structure work? Allowing repeated saving without leaving the passage?

Thanks!