To my awareness, SMF boards that support spoiler tags such as this one are capable of supporting many different types of spoiler tags (see here
for my source on that). This board presently uses the first type listed on that page; spoilers are hidden until they are moused over, and are hidden once again when the mouse leaves the spoiler's frame. The other two types operate by clicking instead; the spoilers are hidden at first, and their visibility can be toggled by clicking on either a link or a button.
The other spoiler settings would be more compatible with nonstandard browser setups including mobile phone browsers, browsers without scroll wheels, and possibly even text browsers (depending on whether they support the mechanism triggered by the click), as all of these are capable of clicking or emulating mouse clicks. Moreover, for all browsers including standard browser setups, the alternative spoiler settings would make it more convenient for users to see the contents of spoilers hiding large blocks of text. It may be worth considering either changing this setting in the default theme or supplying an alternate theme with alternate spoiler formats enabled.