How does the stealth mechanic work?
You can go into stealth, and other ships have a bubble around you can see on your radar (the radar is also much better than in EV). If you get inside that bubble you'll fall out of stealth. The size of the bubbles scales with the mass of your ship, so a shuttle or an interceptor can hide very effectively, but massive cargo ships simply cannot.
This makes being a criminal or smuggler much more interesting. In EV there was nothing more to it than being super fast and staying ahead of the patrols trying to scan you. In Naev it's the similar, but stealth gives you more options. It feels very cool to be drifting silently in space, waiting for patrols to move away so you can reach the jump point undetected. Feels more deliberate and clever.
Another cool thing is that the AIs use it too. So it feels much more like you've been accosted by a highwayman when you're a little Terrapin trying to finish a mission, and suddenly pirates appear out of the blue (black?).
I always like a stealth system in space that involved not radiating, as well as avoiding active radar, too many sub sims in my youth :D
My favourite thing about The Expanse was when incoming radar stealth ships were finally identified by their bright drive plumes as they slowed for an attack.
That's very cool re: The Expanse. Alastair Reynolds, an astronomer turned sci-fi author, explores "weaponized astronomy" a lot in his books, especially the opening chapters of "Inhibitor Phase". Without too many spoilers, there's a ship that cools it's hull close to absolute zero and uses cryogenic gasses for thrust in order to maneuver, so that it isn't radiating IR. And they have to time their operations so that they aren't seen occluding the sun.
Also a good space opera, as well.