When you use a reference selector (dropdown) It is possible to determine selectable objects by Database, XPath or Microflow. You find this in the third tab when you go to the properties of the reference selector (see screenshot).
You can try using https://appstore.home.mendix.com/link/app/56183/ this widget in combination with some conditional visibility to restrict enum values. Please make sure you validate the selected value in the microflow saving the object as conditional visibility != security .
Maybe the inner workings of the reference set selector improved in a way useful for you. Check the release notes of 7.12:
Association Widget Improvements
We improved how the Mendix reference selectors (reference selector, reference set selector, and input reference set selector) interact with their select page. From now on, if the select widget (data grid, template grid, or list view on the select page) has some non-trivial configuration of what objects to show (for example, an XPath constraint), this configuration is not overridden by the Selectable objects configuration of the reference selector. Instead, the two filters are taken into account. For example, if you create an input reference set selector with selectable objects limited to one satisfying an XPath
[Status = 'Done'] and on the select page you place a list view showing only objects satisfying an XPath
[Age < 10], the user will be able to only select an object satisfying the combined XPath of
[Status = 'Done'][Age < 10].
I am not able to use refrence selector for enumeration value.