At present the thumbnails and thumbnail stacks in the extras tab apply to the whole tour. A good extra would be to have the option to apply a thumbnail/stack to a single panorama.
Someone asked me for a tour showing various places at different stages of development. The above idea would make this possible.
Sorry - i misunderstood your question in the first run . .
You can deactivate the visibility of the stacked thumbs - or any kind of thumbs - by editing it in the exml.
So you can select where you want to have it and where not.
And you can changed that anytime back.