Guys, you are free to do customization of any kind and it is encouraged.
But remember, if you face any issues with the code afterwards, and come over support helpdesk with some issues, our first response for you will be to revert back to the original files.
Always keep a backup. Always know what you are getting into.
I am writing this right now because a user applied similar customization (I am guessing he copied from this page itself) and came over support saying the Google Distance Matrix is crashing the Cart page. We had to spend hours figuring out that the issue was with the customization he has made and he didn't mention it.
His support is terminated for wasting our time.