Exclude screens from prototype

Hi,

We currently have a lot of projects in InVision, so to keep a decent overview of which ones which, we create a dedicated "Thumbnail" screen which we put first in every project. Previously, we could upload a thumbnail image, but this has since changed. When we're sharing prototypes internally this is not an issue, but customers have on several occasions asked what that screen is for. Of course we explain it's use, but preferably we would like to hide that screen altogether from sharing links.  Is there any way of doing this? Would be nice since we both use InVision to present designs for customers, but also use them for specs for our developers, so a lot of the screens we have are often too specific or technical for the customer to need to see.