Will simply adding a 'Allow Cross Origin Requests' to my node app work?

I'm trying to make a 'frontend web scraper'. I had the idea of setting up a node app that had a dynamic route that used Request (the NPM package) to scrape pages and displayed them as it's own. Then my JS plugin would add an invisible iframe to whatever page it's used on with of 'http://ift.tt/1CdNHnL]'. Then use the inter page getElementById() function to get the text. The reason I ask this question is because I know that you can't use getElementById() across multiple origins, but if I was able to get the page on a heroku app with a 'Allow Cross Origin Requests' header would this work? I know my question is very confusing.