Rails ActiveAdmin modifies resource object

I currently have a custom object, but to avoid redundancy, I would like to wrap it in a presenter object called MerchantUser / ProviderUser. However, with ActiveAdmin, I am a little confused on how to do this. I tried to use before_create to change the user in the respective presenters, but in the ... do index, I can still see that user.class is User, not the wrapper classes I have defined.

I looked at scoping_collection, but unfortunately this only works with collections and not individual objects?

 ActiveAdmin.register User, as: "Companies" do # rubocop:disable Metrics/BlockLength
  before_create do |user|
    if user.merchant?
      user = MerchantUser.new(user)
    else
      user = ProviderUser.new(user)
    end
  end

  actions :all, except: [:destroy]
  permit_params :name, :email, contract_attributes: [:id, :flat_rate, :percentage]

  filter :role, as: :select
  index do # rubocop:disable Metrics/BlockLength
    column :name do |user|
      user.name <---I want it so I can just do this without the if/else blocks like below.
    end
    column :role
    column :contact_phone
    column :email
    column :website do |user|
      if user.merchant?
        user.company.website
      else
        user.provider.website
      end
    end

    column :flat_rate do |user|
      money_without_cents_and_with_symbol(user.contract.flat_rate)
    end
    column :percentage do |user|
      number_to_percentage(user.contract.percentage, precision: 0)
    end
    actions
  end