As a user, I can tag backlog items, so that I can quickly differentiate between them

[51ngul4r1ty]

In the plan view the "mix" of items all blends together. If they are tagged (and the tags are visible in this view- color coded by user choice) then it will help to differentiate them visually without needing to drill down into the details. Github labels tend to differentiate items like "feature" or "bug", but Atoll already has different backlog item types for this so this is intended for other uses like:

1. Technical user stories can be tagged "tech" or more specifically "spike", "dx", "tech debt", "hardening", etc.
2. Feature user stories can be tagged "needs to be refined", "ux", etc.

Until the "milestone" feature has been implemented it could also be used to differentiate items for specific milestones as well.