I think to limit RNG we can do Vault Any% and Voyage Any% categories. Voyage Any% being you do the entire voyage and hope for good island and vault RNG, where as Vault Any% could be you start the timer when you put the key on the podium to when you pick up the chest of ancient tribute. There could even be a 100% categories for both where you need to get every map piece and for the vault require all the chests (not gold) are out of the vault, timer stops when you drop up the last chest right outside the vault door