Using only SharePoint groups to show/hide custom actions is far too limiting to make the feature truly useful.
I have a specific case where I want to hide a custom action if the "Status" field is not "Submitted". I also want to hide the custom action if the current user is not in a particular SharePoint list(not a SharePoint group) even if the field "Status" is "Submitted".
There are many technical reasons in my specific case why I cannot use a SharePoint group here. I need the flexibility of including list lookups and field value tests.