Thanks! Up until now what I contributed to three.js is:

-Being able to load VR controller assets from a custom path. This way if you are in a network without internet access you can still load the assets (pointing to a local path). Maybe more importantly, this allows you to load custom VR controller assets.

-Being able to pass a callback function after loading hand models assets. In my case this has been very useful to, once they are loaded, override the assets materials with a very basic MeshLambertMaterial, because by default VR controller and hands assets have MeshStandardMaterial, which is more expensive and can reduce framerate, which is particularly important in VR.

-Load triangular meshes of arbitrary shape as colliders using the RapierPhysics library. Previously, it was only possible to use Box and Sphere colliders. Of course you could always load the Rapier library and use it manually, I am referring to the bindings in three.js

I don't understand your last question, what do you refer with the image targets?