Storemapper code will run a callback when it’s loaded called storemapper_callback. In that you can access the Google Maps Javascript object with Storemapper.map and with that you can update the settings to anything in the Google Maps JS API documentation.
To disable map zoom on mouse scroll we recommend putting this inline in a script tag directly below the Storemapper embed code like
function storemapper_callback() {
Storemapper.map.set('scrollwheel', false);
}