User Migration from one Server to another

I’m attempting to migrate the User Information List from one server to another as we’re migrating a site from a 2013 server to a 2016 server. Some of the data being transferred requires the users from the 2013 servers to persist to 2016, even though some of the users don’t exist or no longer are active in AD. I currently have a powershell script that will export users from one site and import into another, but it will only add the users that currently exist in AD. I’ve tried creating a new list item, as well as using EnsureUser(). I’m out of ideas as far as this issue comes. Would anyone have any other options I could try?