At one point I wondered if the Flare Star adventures had been set in an earlier period, but based on a review of other Keith brothers material, it seems clear they thought that Reaver's Deep was still wild enough in 1105 to support trade pioneer teams. Here's a list of worlds in the Deep that were canonically opened up after 1000 Imperial:
- 1030 - Gaajpadje (Reavers' Deep 1124)
- 1058 - Roakhoi (Reavers' Deep 1224)
- 1080 - Lajanjigal (Reavers' Deep 1721)
- 1109 - Htalrea (Reavers' Deep 1226)
So now the question is, how to justify having so many worlds remaining so wild for so long.
Here's my working theory, and would be glad to hear other ideas. The Peace of Ftahalr demilitarized much of Reaver's Deep, but also restricted the signatories' holdings and economic interests in the region. The signatories, their allies, and vassals/proxies could not directly own properties or businesses in the Buffer Zone. Companies with any ownership interests from the Imperial family or signatory clans could not do business in the Buffer. This means the largest corporations in Aslan and Imperial space were blocked, and the penalties for circumventing this ban were just too great to justify the marginal benefit of circumventing the Peace.
All signatories were so scrupulous about respecting the treaty terms that they virtually abandoned the Buffer Zone overnight. As a result the Deep, which had only just begun to emerge from Long Night, crashed back into economic recession and technological regression following the Peace. Many worlds were abandoned or cut off again from the interstellar community. While neighboring regions were able to grow, the worlds of the Deep slid backwards until the mid 500s, when various interstellar polities began to form. These governments slowly expanded to neighboring systems, but isolated clusters and systems remained fairly untouched.
Meanwhile, the signatories spent considerable energy ensuring that third parties outside the Deep also respected the terms of the Peace. Both sides saw the benefits of maintaining a larger Buffer between them. While the IISS included the entire Deep in its Second Survey, the resulting dataset remains restricted in order to discourage exploitation.
While the signatories continued to abide by and enforce the Peace for outsiders, they increasingly exploited workarounds and loopholes themselves. The Imperium, for example, cultivated a few select client states -- though such moves were quiet and limited in scope.
By 900 the Solomani Confederation was beginning to poke around the Deep, spurring more interest from the Aslan and the Imperium. The independent polities of the Deep began to meet and compete, and after 1000 began to aggressively seek out trade with isolated or lost worlds.