Have no fear, Magi. It can be done. Make sure that you are added the component to a layer for an assembly, not a part.
You can still see the dimensions even if a component is on a layer and blanked.
There's also View > Model Setup > Component Display. You can set the display of the spacer to wireframe, hidden line, or no hidden mode, while keeping the rest of your model shaded. You can apply this to components in assembly mode, or surfaces in part mode. Very handy.