I was hoping to avoid rotoscoping if possible for this project.
Thanks for the tip Kalleheikki, I found a solution similar to what you described.
What I did was create a shape layer and draw the points in 2D space to roughly match the 3D nulls controlling the wireframe layer.
I found a tool “create nulls from paths” which generates nulls for each point of the shape layer, with each point then following the nulls.
I then made these shape layer nulls 3D layers, snapped them to the positions of the wireframe nulls, and parented them so that they copy the transforms.
As my shape layer points follow the shape layer nulls, and the shape layer nulls follow the wireframe nulls, the shape layer accurately matches the outline of the wireframe.
Thankyou!