The solution may eventually lead to data integrity issues like I experienced a couple years ago with a product file of nearly 3000 items. CSV imports and exports of product data should not be the main method used to make large scale data changes because of increased risk of data corruption. It should be handled on Loyverse.
A simple task like your request should be doable just like you said, from the item list screen. Export via CSV and re-import just for that? Sure it works, but it is inefficient and one day you will experience the CSV data implosion.
As shared previously many times, it is time for Loyverse to have its own native product management tools for bulk changes. Here is an example of an excel-like interface used in a WooCommerce plug-in.