Figured I'd add my take on slipstreams in case no one's said anything similar before.
As much as I really hate (in the moment) going around or e-burning through them when I run into them randomly, I think they're a perfectly reasonable obstacle. As a utility, though, I think they'd be much more meaningful for me at least if, for example, slipstreams were visible on the star map within a certain radius around your position, ideally a radius a few times larger than the maximum amount the camera can zoom out.
It may just be that my brain is small, but I find that 95% of the time, slipstreams are useless and moderately annoying to me simply because there isn't any clear way to factor them into my travels. Nearly every time I see one, it's something I didn't plan to encounter and is simply either not useful to me at the time or in my way. There have been a very small number of occasions where it just so happened that I found one leading more or less in the exact direction I was already going, but these instances are rare.
The issue could also be I'm just not thinking of ways I could be using them. I do that a lot in any game and in life. Plus in Starsector I always play in what seems like objectively the wrong way (based on how ships are outfitted automatically by the game and the way people design ships in mods), at least where combat is concerned.
It really isn't as big of a deal as I might be making it sound, but seeing how I always use an absurdly huge map thanks to the Adjusted Sector mod, I think it would be neat to have the ability to plan voyages to some extent using the chains of slipstreams that pop up on occasion. Just an idea I think sounds neat.