Can components of an instanced mesh spawned using construction scripts be interacted with?

I spawned in a large amount of blocks using instanced meshes in construction scripts in a 30x30 square.

Now that I’ve placed all the blocks down I want to make small edits to the their location data. Move some blocks up to give the scene some Hight. Delete some blocks when I add stairs. Is there a way to select individual blocks now that I’ve created them with construction scripts.

Another question: Is it possible to change the material of individual instanced blocks using instanced materials?