Object pooling vs Instantiate for relatively small amount of objects

I have a scene with 10 platforms and about 30 obstacles on them.

Should I instantiate the platforms and the obstacles and destroy them when they are behind the player (outside of the camera).

Should I use object pooling or just re-position the inactive platforms/obstacles according to the camera view.

Is the memory not fully freed even after the reloading of the scene? Because if the memory is freed, 40-50 objects instantiated and destroyed seems like no big deal (they are primitives - cubes, spheres etc.). I was reading a lot on forums and there were some tests done by other people, however I can't make a conclusion.

P. S. I am reloading the same scene and just increasing the "level" count. I am making the game for mobile. The game is 3D.