My reply is based on my personal experience and impressions of these animals. Other opinions are equally as valid and I know of keepers that have female veiled chameleons in larger enclosures than mine and the animals are fine.
No one is right or wrong with this one.
I am pretty sure of the fact that my girls are healthy and content, and I see no reason to change their situation. In fact in a larger habitat I have witnessed them acting, what would have to be described as, hyper vigilant. I believe that keepers who have reported that their female veiled loves her giant enclosure and explores every part of it, are actually witnessing her reacting to the anxiety of feeling exposed. It would be interesting to know how active they are in a natural environment. I suspect that they are content to remain within a pretty small radius. It would also be interesting to observe what kind of cover they seek.
-Brad