From the thoughts instigated by Ben Kelada on MDL-33115, I have updated the toggle event handling code and one bug fix. You can get the updated versions from:
M2.4 -> https://moodle.org/plugins/pluginversion.php?id=2875 - edited to update to fixed version.
M2.5 -> https://moodle.org/plugins/pluginversion.php?id=2876 - edited to update to fixed version.
Also, the code should be more efficent in it's use of the YUI JS library, but I have not undertaken bench mark tests to determine this.