If you only need to pass 1 value through - simply dig into the form and get the value manually using the $form jQuery collection parameter in the onFormSubmit callback:
onFormSubmit($form){
var email = $form.find('input[name="email"]').val();
var redirectBase = 'https://www.google.com';
window.location = redirectBase + '?email=' + email;
}
the reason your URL is breaking is because my previous script had a flaw. There are better ways to go about it - but for simple 1 parameter redirect logic - the above is as simple as it gets.