Have many objects with the same material, yet only want to render a small subset at a time, what's the best solution?

So, I have these spheres in my scene that work as controls for the user. I just want to render none, one, or a small subset of them at a time.

A few approaches I'm considering:

1) simply turn off the the mesh renderer or object, and turn it on when I want to interact with a specific control. 2) create material instances for each sphere or group of spheres (to change the alpha of the color) 3) modify the material block as needed (change the alpha)

Which is most performant? Are there other solutions to this problem?