I've cobbled together a VERY rough outline of my Visions of Empire setting. I am leaning towards having the whole thing be a Traveller sector. Black are (sub?)sector names; red are the alien species present in a (sub?)sector I have not yet named.
I'm trying to decide between my empires being 3x3 Sectors in size to my empires being 3x3 Subsectors in size (known space is 4x4 sectors/subsectors in size). On one hand, having multiple sectors per empire is more epic and allows for a much bigger frontier and post-frontier, especially given centuries of Imperial rule (though both empires weren't very expansionist and expanded slowly). On the other, with 3x3 Subsectors, I can fit almost all known/relevant space in a single Sector and make everything manageable; even roll UWPs for all worlds in the "universe", which is tempting, and really, do you really need all these random/dot-mapped worlds for a campaign?
(Note that this setting uses mostly CT Books 2 designs and Book 3 drive TLs, so you can get Jump-4 as early as TL10).
The options I'm toying with are:
1) The entire known space is ONE sector, plus a beyond-frontier area, one subsector thick, all around it (so, 6x6 subsectors total). Manageable, but less epic.
2) Map ONE sector for the game, but have 15 other sectors as background (unmapped or dot-mapped).
Currently leaning towards option #1.