Modal Link Label
As previously stated, this and all other settings for VPS are to be found in the Input Tab when editing your page field with a Visual Page Selector inputfield. Specifically, the setting is under VPS: Page Edit Settings.
In this setting, you enter the text to be displayed in the field's Inputfield, for the link that opens the modal for adding pages to your page field. Technically, it is the link that opens ProcessVisualPageSelector.