Kia ora koutou,
So it looks likes trial groups might have to do a fair bit of prep work to gather keys and mementos before doing the Opulent Ordeal. I don't know the full details because ZOS did reduce some of that work during PTS IIRC.
It would be funny to see what three full trials teams could do to the Night Market if they were coordinated enough to go through each district together wrecking everything they found. I realise that coordinating groups of more than 12 players is difficult, but I've seen it done before.
Ngā mihi,
Eurymachos