Oh right!
Sorry Paul - it seems most distros default to JACK2 now so thats what I've
been using.
Looks like I need to take up my issue with the JACK2 devs then and you can
probably close my feature request now
Thanks!
Dan
 current jack1 (released months or years ago):
  if (snd_pcm_open (&driver->playback_handle,
                                   playback_alsa_device,
                                   SND_PCM_STREAM_PLAYBACK,
                                   SND_PCM_NONBLOCK) < 0) {
                         switch (errno) {
                         case EBUSY:
                                 current_apps = discover_alsa_using_apps ();
                                 if (current_apps) {
                                         jack_error ("\n\nATTENTION: The
 playback device \"%s\" is "
                                                     "already in use. The
 following applications "
                                                     " are using your
 soundcard(s) so you should "
                                                     " check them and stop
 them as necessary before "
                                                     " trying to start JACK
 again:\n\n%s",
                                                     playback_alsa_device,
                                                     current_apps);
                                         free (current_apps);