The desired result is on the bottom, the current result is on top. This might be done by calculating each underground segment using the underground cost(so 6x the cost for a full length yellow, 8x for red, and 10x for blue. 1 for each end and 1 for each underground segment) rather than just the ends themselves.

https://kekpe.pe/i/5fa8c9263dccb.jpg

I don't think people want this? The current version saves more belts and allows more transport lines to pass through. I remember there are also people posted on discussion that wanted the result on top rather than bottom.

I think it looks cleaner.

Hmmm okay, will add a setting for this in future

Thanks! You may be the most responsive dev in the history of devs. Even more than the Factorio devs themselves.

No problem :) 1.3.3 now supports settings to the preference

Hello. Sorry to bring this back up, but I have noticed that some configurations result in incorrect underground length, even with the option set correctly:
https://kekpe.pe/i/60070001a24f9.jpg
(in this example, the first two spaces of underground length should be above ground.)

Hmm interesting, I guess it's because when the algorithm found a connecting point to the ending belt, it stops finding better cost paths..

Thanks for the info, I might fine-tune the algorithm somehow in following days.