Instead of implementing an item list feature into this script, I remembered a suggestion by @Kumirei [1] and decided to create a companion script that registers your filtered items in an Open Framework filter:
This allows you to view the item list in an already established and feature-rich tool like Item Inspector. With Open Framework Item Filter and Item Inspector installed, you just have to locate the Item Inspector on your dashboard, click the settings gear button, go to the “Tables” tab, add a “New” table list, give it a name, find the “Item Filter” checkbox (probably at the bottom), and activate it. After saving, you should see a list of all your filtered items.