Collapsable lists in page selectors regardless of list size

[matthewshields]

As of today a list published as a page selector dropdown doesn't offer the +/- expandable tree in a page selector when the list surpassed 1,000 items including parents, and this feature is disabled, much like the list settings page stops you from using a tree after a certain size.

I understand this is a performance issue, but it would be great if we the model admins can turn this on and off for smaller models when the benefits outweigh the costs.