Preview of my game level in editor to place turrets

Hi,
I am making a simple shoot em up game.
I am using GameObject pooling to make it more performant, so my turrets are not present in the scene view in the editor because they are created in pools on first load of each level.

I would like anyway to place my turrets in place into the editor to be able to view the effect and exact position with other level objects like terrain.

How can I preview my turrets in the Editor in the correct position and all at once in the world and then switch to pooling on game play?

Thank you
Camillo

 

Maybe it is a simple question, but I would like to understand what are the best practices in designing a game level which uses object pooling.
Thank you
Camillo