Does the BG3 Toolkit allow for adding custom 3D models?

[RiseAgain]

This would be great for modding, as it would allow players to create new creatures and characters.

[tonypa]

Sure, you can start by following this guide explaining how to add custom dice:
https://mod.io/g/baldursgate3/r/adding-new-dice
More complex 3D models (with animation and interaction) take more work.