Use of People field type

I have a need for a custom field that will list the names of people. Requirements: (1) Names must not be tied to user accounts in Asana, (2) list must have the ability to include 2000+ names, and (2) need the ability to report/filter on those names.

Option 1: Custom field with People field type. Problem: This field is tied to the user list in admin console and the field gets wiped if that user leaves the organization or account is removed. We need the ability to keep the name for historical reasons.

Option 2: Create a project that lists all of my people as tasks and then add a custom field to other projects using the reference field type based on tasks in that master project. Problem: Reference fields cannot be used as filters in list/board views.

Option 3: Create a multi-select field type and add names to the field values. Problem: single-select/multi-select field types are currently limited to 500 values.

Does anyone have a possible solution for this dilemma? I would love ideas.