I have to correct myself. These are some results for example 5:
With set_default_validate_args(True) and N_ITERATIONS=32
DURATION: kernel launch 0.4117265930000258
DURATION: kernel complete 1.801716031000069

With set_default_validate_args(False) and N_ITERATIONS=32
DURATION: kernel launch 0.019914979000077437
DURATION: kernel complete 1.801976835000005

With set_default_validate_args(True) and N_ITERATIONS=512
DURATION: kernel launch 6.590126628999997
DURATION: kernel complete 8.072248363000085

With set_default_validate_args(False) and N_ITERATIONS=512
DURATION: kernel launch 4.870119396000064
DURATION: kernel complete 7.648874833000036

Is there something else I am missing? There seems to be a big difference in launch time depending on N_ITERATIONS.