It's 100% clientside.
All this does is set some settings like:
cl_threaded_bone_setup 1
cl_threaded_client_leaf_system 2
r_threaded_client_shadow_manager 1
r_threaded_particles 1
r_threaded_renderables 1
r_queued_ropes 1
studio_queue_mode 1 (or mat_queue_mode -1 in gmod's case)
cl_threaded_bone_setup 1
M9KGasEffect 0
gmod_mcore_test 1
Not dissing on this but it really does not need a server suggestion but more of a topic if founders want to look into it more as suggestions for people. You could legit just edit your autoexec file that gmod uses and include everything this does.