Hey.
We currently don't have that.
But note that images don't even need to come from Texture Packer. It can also come from Unity sprites.
We've improved the examples and API in the new Spine-Unity runtime unitypackage for Spine 3.6.
If you're very familiar with the innards of TK2D, you can check Spine-Unity's AttachmentTools.cs
code to see how it's achieved with UnityEngine.Sprite assets.