Board Thread:Support Requests - Getting Technical/@comment-5558012-20150528162416/@comment-24409505-20150530095709

To make it only expand when you click on it, remove all of 452's codes and then add this:

.editor-open .editarea textarea { height:600px !important; }

Change the number to whatever height you want, original is 200px. It works in the forum, message wall and comments section in articles and blogs.