I've used one on an E3. I wouldn't be able to use it on a daily basis but for occasional trips it was manageable. It sticks out quite far when the doubles seat is on and made my back ache unless I stood to the side and pushed.
Thanks, so it can be done but not ideal. How was it without using the doubles seat? Does it still stick out far? I will be needing to use buggyboard everyday but won't need to use doubles seat everyday.