If you're looking to improve your Season 3 Raid UI, then WeakAura and UI guru Reloe has you covered with his Major Amirdrassil Raid Mechanic WeakAuras used for progression. The suite of WeakAuras has been updated up to Tindral Sageswift with Fyrakk likely being added soon.
Reloe is a self-proclaimed «WeakAura Guy» that has been creating and maintaining comprehensive WeakAura and other UI addon packages to help players defeat the latest content no matter the difficulty. He's worked as a consultant to various Race to World First guilds to create some of the most advanced WeakAuras to overcome many complex challenges in WoW.
If you're interested in more of his UI work, feel free to visit his Discord.
Reloe has created a set of Custom Auras that should help players quickly handle assignments deal with particularly difficult mechanic including:
Major Amirdrassil Raid Mechanic & Assignments WeakAuras by Reloe
If you're looking for something a bit more comprehensive rather than just the macro mechanics and assignments, then be sure to check out Reloe's Full Amirdrassil Raid WeakAuras.
Full Amirdrassil Raid WeakAuras by Reloe
The above imports will be continually updated throughout Season 3. You can use the above links to manually install those or you can use the WeakAuras Companion App to automatically install most of the updates as they become available.
WeakAuras Companion App