At the time of the Dynasty Expedition, ships used type 2b hyperdrives, not Frame Shift Drives (type 3), so there would have been no FSD boosting. Their range would have gradually increased as they dropped off beacons, which presumably allowed them to get as far into the Rift as they did.
.
This raises the question as to why set beacons (around Earth-like and seemingly also terraformable worlds) over such a wide region? If, as many people now seem to think, they were laying the ground for future colonists, then why not distribute them in more confined regions, so that the different colonies can easily trade, communicate and also protect each other? The seeding of terraforming candidates seems to demonstrate quite conclusively to me that they were laying the foundations for someone to go back and live there - but in what numbers and for what reason? What is special about this part of space? Are the future colonists people looking to get away from the bubble, or is there something in/near the Rift that they want to move next to? A lot of these questions will have to wait for Premonition, or at least the 29th, though...
.
I would like to think that there are other mega-ships, or at least wrecked Anacondas, in the Hawking's Gap and the Conflux but that is wishful thinking. If the same thing happened there as on the Zurara, then perhaps they might have been destroyed and the Zurara is the only surviving mega-ship of the expedition. It is certainly worth looking but without clues it would be extremely difficult. I think there might eventually be beacons added around some planets, however, and that these could help lead us to wrecks, or provide information themselves. Perhaps we need Salomé or one of her friends to survive the 29th, so they can tell us what frequency the beacons use, to help us locate them...