Unity 2D Sprite Packer and Packing tags taking effect immediately after setting up?

Hello!

I have a question regarding Packing Tags on 2D games. I’ve been building my project roughly for 4 days now, and only today I found out about Packing Tags and Sprite Packer. Some of the level design is already done without using either of the tools mentioned, and now I’m wondering whether I should build up my level designs again.

My question is as follows:

Does Unity immediately take the Packing Tags into use after setting them, or do I have to redo my level design and drag all the sprites into place after setting the Packing Tags into the scene in order for the advantages to come into effect?

Thank you in advance! I hope the question is clear enough.

Its not necessary to rebuild your levels, you can define Packing Tags at any point in your Project.
You need to change settings in Edit->Project Settings->Editor->Sprite Packer->Mode->Always Enabled to reflect the changes both in Play Mode and in Builds.