For general objects, you can toggle visibility from More Visuals > Show 3D Shape in the properties. You can also do this by right-clicking the object and selecting Edit > Show 3D Shape.
For conveyors, you can hide them by right-clicking > Edit > Show 3D Shape, but it is very troublesome to show them again, as you cannot access them from the properties.
Could you please add More Visuals to the conveyor properties as well?
I would also like you to add it to stations, control points, and other objects that do not have More Visuals.