Just as a followup, Decker 1.66 makes this technique a tiny bit more powerful:
By altering app.cursor it's possible for blocking scripts to override the appearance of a mouse cursor. Setting
app.cursor:"point"
While the mouse is over a clickable "button" (real or simulated) will improve the illusion that there's a real widget there.
The new gamepad interface opens up additional input options, too: the "left"/"right" directional buttons and the "cancel" button aren't used by Dialogizer, so any of them could be used to exit a game, mute sound effects, summon a menu, etc, via the keyboard or a physical game controller.