There are several ways to edit a level (vector or otherwise) that is being driven by a mesh.
The key to all of them is to expose the level on a frame that doesn't have a mesh attached.
I like to extend the exposure by 1 frame and then edit the level on that frame.
We can also move a cell of that level's exposure to another column that does not have the mesh column as its parent.
The way many users edit the frame is to shift over to the Level Strip and edit it there.
- Rodney