If the part is meant to be cut though, you can just “use” the whole thing. I name them something like “top_cut” and I just push them all the way to the bottom so I don’t accidentally depend on them. Maybe next time, you won’t work so hard on the first sketch is there’s an easier way to do it with the 3D stuff.
Fusion doesn’t work in Linux, OnShape does. So I’m not a fan of fusion. I saw this old Tony doing some CAM in it and it finally seemed to make sense, but I haven’t tried it since then.