I get your point, but I would like to see how the current arrangement works before changing it. In practice, I think it will be hard to set up such discontiguous outposts because you'll have to use slow ships to do it. And once you've decided to send a fleet of slow ships to the other side of the galaxy, there's no impediment to creating sector capitals on the way. So even if we required a contiguous region, it wouldn't take much longer to do it.
Another reason for deferring is that restricting to contiguous regions is much harder to implement. In particular, we'd have to do all the same pathfinding that we do for nebulae. But unlike nebulae, which have a pre-computed mesh of points, we would have to dynamically adjust the pathfinding mesh every time a beacon is created or destroyed.
Plus we'd have to handle the case where beacons appear or disappear while jumpships are in transit. If a beacon disappears the jumpship would have to move to the edge of its current zone and then either stop or go at slow speeds to its destination. And if a beacon appears while a jumpship is in slow-mode, it needs to speed up. In both cases it's lots more code.
There is one current bug that I want to fix, though. Right now, for F&M doctrine, a jump beacon appears as soon as you designate a sector capital. It should instead wait a full cycle until the sector capital is done.