I am at 10-12 voyages without unlocking now, I have tried virtually every combonation for zones 16, 17, 20, 21, 22 as my trips. RNG sucks, SE sucks, It's like the 4 months we spent on making max tier airships was pointless when you could have the lowest possible ship with 90 survey doing the same thing. There is little point in the loot as most of it can be bought faster in Diadem with the currency outside of the minion/housing mats but the market board has already been flooded with all of those items pre-3.1 launch.

On a side note, the only thing I have not tested is the actual parts on my ship. I have all the ships at 59+ component setup but not all ships have a Tatanora part on it, could this be part of unlocking Diadem? Having at least 1 tatanora part on a ship?

Possibly in the future put what your ship setup was after unlocking Diadem?