I hope my broken English is understandable...
Problem : The trading system does not calculate correctly a Route Length, and VERY long routes are totally ignored.
I do not know if this issue existed before 4.2, as I was waiting for 4.2 for playing the game on the maximum map size, with my new PC.
Settings : Game on Ludicrous size (largest possible), Godlike, 87 starting civs i.e. all game civs + Nexus' designs. Map is the one generated by the game and not edited. Currently 1.575h with all achievements done, talk about being in love with this game ...)
On recent PC with maximum configuration : Mb Aorus Master x570 v1.2; cpu AMD Ryzen 6950X, gpu Asus/AMD Radeon 6900XT, ram G.Skill Ripjaws V 4x32Mb (128).
File : https://uptobox.com/w8zzte0wsiyj
(more explanation in posts below)
My starting position is around top left of the map.
Traders are sent to almost the longest possible path, 3 civs located bottom right, hence a long diagonal. They were all produced in my home planet. This planet was never attacked/taken ... yet ... (hence origin/tracing never broken and trader arriving at destination has original data)
The very remote access was discovered after using the Wormhole Generator, sending a fleet of architects "Bold Enough To Go Where No One Had Gone Before"...
Then I send the traders, designed especially for this task (speed!), on a very very long Hyperlane journey. keep in mind: it is the largest possible map. And it is really insane, even for a top-of-the-range config...
Unfortunately, when I see the yield, it is only very basic income, as it is calculated as if the route length was only ... 1 hex !!...
Even less than a trade with my 22 hexes neighbour (Onyx)
2 examples :
I tried also with the Trireme (double yield, it re-spawns if destroyed), idem.
(and by the way, The Fissure, even if it says "2 logistics", still does NOT accept to be included in a fleet for 2 logs...)