How to import rig with Tool bones

I’ve been working on this edited rig to support smooth tool animations. I have two bones set up per hand as shown here:

image

Though when I use the 3D importer or rig importer, it’s not importing these tool bones. Is there any way to have the importer include these bones?

(disclaimer: since there was no Development Support category, I wasn’t sure where this post would belong. I apologise if it belongs in a different category)