What it Does

It mirrors and links the shapekeys between 2 objects, so they're always in sync.

In other words:

• If the binded object doesn't have shapekeys the active object has, it'll create shapekeys for the binded object and automatically link them through drivers.
• If shapekeys are deleted in the active object, they'll also be deleted in the binded objects.
• If the binded objects have additional shapekeys that are not in the active object, they'll be deleted by default when binded (But there is a toggle to keep them)

Where to Find it

Properties > Object Properties (Green triangle) > Shapekey Binder

Caveats

This plugin was mainly made for myself, so keep in mind it might break fairly easily. Here's some stuff i'm aware of:

• Renaming the binded objects could cause problems, so unbind before renaming.
• There may be a bit of slowdown when creating new shapekeys on the active object.