A video explaining the basic functionality of the WeakAura: https://youtu.be/2SynZ2KFjLY
This WA makes it possible to automatically switch between Equipment Sets by hovering over, targeting and/or killing NPCs in any Wotlk raid (…Hitcap/Trash/vs Undead or Demon/Resistance Gear - you name it) by utilizing the AddOn ItemRack/Gearquipper (see Curseforge/Twitch).
Specifically, it can equip pre-defined sets of gear in various ways:
1. Entering a raid.
2. Entering a raid's subzone.
3. Hovering a boss.
4. Targeting a boss.
5. Killing a boss.
Currently this WA only fully supports English. The things that don't work for non-English clients are gear changes upon entering a subzone (e.g. equipping a specific gear set for Mimiron when entering the Spark of Imagination subzone).
Switching is very useful, as "optimal gear" usually differs greatly between individual Bosses and Trash. Especially for Trash you can switch out +Hit for far more valuable bonuses or where specific trinkets are better suited for the individual trash laying ahead. Healers may also benefit from exchanging +Heal/MP5 sets. Perfect equipment switches create an advantage in speed runs and parse-oriented gameplay.
This is based on the Classic TBC WeakAura by me: https://wago.io/DAkjwWwWI - which itself is based on the Classic Vanilla WeakAura by Zippy: https://wago.io/_ah46FI84