Ensure the JavaScript behavior is executed only once per page

I hoped this would be a simple revision of the JavaScript behavior making use of Drupal core's once library, but that doesn't seem to solve the issue. Now instead of always getting 5 iframes, sometimes I get none, and sometimes I get 5. Will keep digging.

Turns out the library itself being included multiple times per page was the issue. I went ahead and converted all three JS libraries to remove jQuery and add Drupal's once to prevent multiple application of the behaviors. All works great now!

No clue how this got reopened; closing again.