How to change the Drupal Commerce Stock formatter? Drupal Commerce Stock displays the correct number of stock. For example:

Product Name, Price: $ 1.00, Stock: 20.

I would like to change the stock levels to 1, 2, 3, 4 and 4+. So if the stock level is 5 or more, the displayed stock will be 4+. What's the best way to do this?
If you want to display the stock of a product with 4+ when it's >5, assuming that you've got stock a field attached to the product and exposed to the node display (default behavior) you can use hook_entity_view_alter or hook_node_view_alter to alter the #markup of $build['product:field_stock']