He escrito un script de AppleScript que alterna el estilo de Zoom:
tell application "System Events" to tell process "System Preferences"
activate
tell application "System Preferences"
set the current pane to pane id "com.apple.preference.universalaccess"
reveal anchor "Seeing_Zoom" of pane id "com.apple.preference.universalaccess"
end tell
delay 0.5
tell pop up button "Zoom Style:" of window "Accessibility"
click
if value is equal to "Fullscreen" then
pick menu item "Picture-in-picture" of menu 1
else
pick menu item "Fullscreen" of menu 1
end if
end tell
tell application "System Preferences" to quit
end tell
Puedes usar Keyboard Maestro o cualquier otra aplicación de inicio de script para ejecutar este script en un atajo de teclado.