I'm not comfortable with what you wrote (yet). The easy route for me--right now--is to keep doing it the way that i know. I wonder though, which method works in more browsers (and versions) that support scripting?
Right now, i want to add a Home button to Memrise after a course review (maybe even during a review) or learning session. The top bar changes and it takes extra clicks to get home, even when the session is over.
(Source not shown to do "Filter error: Please use fewer 'junk' characters." And to think, /. used to be for geeks.)
So, the easy way out might be:
var review = document.getElementById('gardening-area');
review....= (add button here) + review.....;
What would you do?