I tend to agree, if a pilot states he NEEDS the entire lenght, we'll have to make it work. That's what we're here for.
One workaround could be an agreement with approach that they make slightly more seperation behind A380'ies when you have traffic ready for departure?
That way you can get one aircraft going without an extra 3 min. delay at the holding point, with maybe only an additional 1 min. to the next inbound aircraft?