You run into an interesting aspect here though:

Where trade routes form is where prosperity exists.

Where strategic routes form is where military necessity exists.

Where communication routes exist would cover both of the above plus another grouping (not militarily valuable, not economically prosperous).

Then, over time, more prosperity would be generated along those trade mains in less prosperous places just because they are on those mains. So, over the long term, prosperity would be created where there are routes. And routes would move where there is prosperity and away from places that are burnt out or no longer prosperous.

Similarly, strategic routes would vary over time based on changes in threats and defensive priorities. They would probably bring prosperity where depots, shipyards, bases, etc. were located.

Communication routes would be less impactful on prosperity by themselves when not accompanying a trade route.

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It would be a fun project to pick a sector-ish size of space with several one-planet homeworlds and stipulate when they respectively get J-1 and then watch them expand and do route determination every few generations to see how things change as we model the growth of a sector sized area. Some empires would prosper, some would fail. Then at some point, introduce Jump 2. And so on.

It might just be very instructive to see how different geography, neighboring empires, and so on impacted trade and whatnot. I love simulation.

I built a large simulation for my fantasy world as to populations in different locations based on arable land, nearby enemies, the math of human migration and natural increase or loss, etc. with some random factors to trigger wars, pestilences, etc. I built the beast in Excel and it worked but it wasn't ideal.

What I need to do is grab a DB, write some code, and be able to evolve sectors in some way like that.

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When you are determining the trade of a sector and thus trade routes, if you just do a sector in a vacuum, do you make no adjustments on the planets near the edges, even just random ones, to represent possible off-map connections?

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I have Astrosynthesis. I generated a 20 ly cubic sector and then tweaked a fair number of the planets to be more habitable. Then I started building empires (maybe 6 of them). I started with the most habitable and randomly generated populations. Then I started on the next most habitable tier. And so on. I still have the lowest tiers to do because they represent the largest number of small outposts, etc. This is a 3D space map. I use the sphere of influence globes with differing sizes by the population level and colour by empire. This gives a very useful informational view of the sector. I laid in manually routes based

I want to run a Traveller-esque game in it (not 3I, but a 2D6 system very akin to and borrowing from Traveller).

I have plans to identify resources and add trade information.

I have plans to see if I can model population movements by year from the initial setup and to randomly generate events of large enough scale to impact human movements and population levels and thus trade.