The file includes the stage model installed at the Metallica Slane Castle 2019 concert. You can make any changes you wish on the iconic stage model at the concert in question.
However, the number of polygons is due to the detailed speaker and light model. You can reduce the polygon count even more by replacing the relevant models with low polygon products for your project.
l-acoustics k1, martin lighting, truss, concert, metallica
extra formats; stl, obj, fbx, 3ds and max