The extrude node resizes an existing mesh, but doesn't initialize new
data for most non-generic data types like shape keys or freestyle tags,
or custom normals. The split edges node doesn't process some
similar vertex data too.
In the future this data can become generic attributes, or it can be
supported in the nodes anyway. But now the new data is un-initialized
after being allocated.
Fixes#106926
80f3f59555