building could allow players to add "custom" starlanes (or "upgrade" existing starlanes to high-speed starlanes) ...
Based on the contents of the public review, all starlanes work at the same speed. This was apparently to ensure predictability... if starlanes change speed a bunch, and ship engines change speed, it's hard to tell how long a journey will take until you make it. Wormholes are, I believe, as separate class of travel, and can work faster, but within "starlanes" there's no variety in speed. Which is why I was keen on the idea to upgrade the size / capacity of the starlane opening... allowing the player to do some strategic upgrading, but not altering the speed of travel.
I'm not sure if making new starlanes was nixed or not, but the widening and discovering ideas basically achieve the same thing.
Thought: To have multiple levels of starlanes becoming visible over time, vishnou00's idea of multiple passes of triangulation might work. The first time, you use half the stars, and make a bunch of easy to see and use starlanes. The second pass, you use the other half, and make a bunch of hard to see starlanes... the "hidden" starlanes grid. Then you run a third third pass and add some interconnections between the two, at intermediate visibility... and also add a random bonus/penalty all over to give some variation. (Could also work with more iterations / less stars per iteration, and / or some overlap between subsets... key difference is that different iterations have different starlane visibility biases)