I'm surprised there aren't any disconnected lane segments. Is there any alternate FTL system that might allow a transit without a jump lane meeting the described threshold?
There actually quite a few stars that are too isolated to connect to the lane network, maybe a hundred or so; I haven´t included any lanes between them because they´re not part of the network. You can assume isolated single systems and small cluster of up to five systems to sit in all of the larger gaps in the map.
There´ll also be many M class stars near those connected by the lane network that don´t have any lanes shown here because, for this preliminary network, I assumed they wouldn´t hold any inhabited worlds - so for this network, they are only included if a stopover there is necessary to get from one F/G/K star to another.
Both decisions are to reduce clutter on the map and make the more relevant features easier to notice.
As for alternate FTL systems, the setting is at TL 12 at the moment; I imagine in the setting´s future a more advanced jump drive may be developed that extends jump lane thresholds by another parsec. I haven´t done a complete check, but that should be enough to connect every star on the map; but it would also virtually eliminate all those rifts, as right now, a lot of what looks like a wide rift on the above map is actually full of 3 parsec gaps between M class stars.
Or maybe an alien civilization from outside the maps area already has such a jump drive, and uses it to go where nobody else can?