To its credit, Goodtask is a wonderful front end to a CalDAV task list that adds a ton of features that iOS' Reminders app does not support.
This also means that you can use another CalDAV implementations such as NextCloud tasks. This allows non-MAC users to use such things as Thunderbird's Lightning plugin to see your tasks and manage them and the Nextcloud tasks web interface.
Both of these products, as well as countless others that support CalDAV tasks, use a field called Categories for tags. Is there any way that Goodtask can support the categories field for tags? This would make the app a lot more usable for Windows and LInux users.