Ah, thank you very much!
When I do no settings, consolidate files and leave the avid-compatibility-box checked (unfortunately all cuts are slipped to frame grid now), the clipgain is transmitted as you described!
…But in this case the standard (vol-)automation is dropped here.
So do I have to export two AAFs - one for translating clipgain and one for automation data - and then replace the clips to get clipgain and automation data transfered…?