We have 4 airships rank 50. One ship has Tantanora body and forecastle on it and takes literally 5 1/2 days to go out and come back if we send it to sectors 18-22. We just did that and no unlock for diadem hard mode and it brought back junk as well (so much for that huge boost to favor and survey). Been sending the other 2 airships to 6 10 13 for chance at motes and potter stones and still nothing as well just 2 items per trip. Crystals and junk items that are no value/use (resin/clay/empty crystals). This dang RNG crap is holding up the entire workshop progress and there's only a small few stages left to do, can't buy the mats either cuz they are beyond overpriced on MB atm as well. It wouldn't be so bad if the trips didn't range from 17-32+ hours in hopes at a RNG chance at obtain an item you need. May have to start using the 1 airship saved for Diadem runs to farm as well to increase the odds.