This is a great suggestion. We try to automatically put the dialog in the right place depending on the action you are trying to perform. For example, if you use drag-and-drop and move something to the right-edge of the window, we move the instructions dialog to the left-hand side of the element.
This certainly isn't perfect and we'll work to improve it. Would you mind sending me the URL you were trying and some steps to repro the frustration you had? Feel free to email us at feedback@optimizely.com
Thanks!