Eye geometry change - workflow ?

Anim

[EDIT]

I solved it by creating a geograft.

[Original Post]

I like to alter the geometry of the G8F eyes. Mainly I want to change the cornea. I don't want to replace the eyes completely.

I can either plan to replace the cornea geometry with a new one or alter the existing cornea by adding / altering geometry.

Is there a right way to do this without the need to rig the new / changed cornea?

- I read, I can change the geometry externally, import it back with "Update Base Geometry". But as I understood it this will change the G8F base which I like to avoid for now.

- Would a geo graft work in way that I don't attach it to the existing geometry but import it as its own part (I would hide the "old" cornea with the geometry editor in that case)? What about rigging in this case so that the new geometry follows the eye transforms?

Am I maybe thinking to complicated?