Activate ALTQ_HFSC, crudely check if it really limits bandwidth as we'd expect.
It's expected, that this command always succeed, so there is no check needed. Correct?
There is a race condition between the "saturate" ping and the test. A busy system might have several seconds between those commands.
Would it be possible to rephrase the check, so that the ping is sending i.e. 10 packets and we expect 3 of them back?