I would like the ability to configure a Selector to require a single member selection on an Entity. Both on screen and in Interactive Selection procedure steps.
Very often screens, navigation, and procedures are designed to work on one member of an entity at a time. For example a trigger in a budgeting application should run only for the selection on the screen. For this, to ensure the user has selected a single member, you can use a pager, or use some logic in the procedure itself to check if the count of members is 1 and only proceed if that check is valid. Along with other work arounds. These add extra steps that may not be obvious to what could be simplified.
Another need for this is that the pager lacks some of the benefits of the selector. The selector interacts with the Screen Select and impacts Dynamic Selections on other entities while the pager does not.
So the developer has to decide "what is more useful?". Using a pager to ensure a selection on one member or making selections interact with each other using Dynamic Select.