It could work with an iframe, though I strongly discourage using it. If you wanted to implement the snippet for an iframe I would switch from using the loadForm method to whenReady, and put it in an HTML block on your LP.
MktoForms2.whenReady( function(form){
//Add an onSuccess handler
form.onSuccess(function(values, followUpUrl){
//Take the lead to a different page on successful submit, ignoring the form's configured followUpUrl.
location.href = "https://google.com/?q=marketo+forms+v2+examples";
//return false to prevent the submission handler continuing with its own processing
return false;
});
});
You'd also need to your take desired location down from the querystring of the iframe in document.location to pass as a variable for your followup URL. I'd strongly recommend using the embed code for your form though, unless your have a compelling need to iframe the form.
Regarding RF, I'm not familiar with how their code works, but it likely doesn't interfere since the form redirect fires on the onSuccess event which is after the form info has been submitted.