So what do you think it means for a species to be inherently stealthy? This isn't stripes helping something to blend into the jungle, but an innate characteristic that makes ships, orbital structures, and planet-based civilizations harder to detect.
It makes sense in the case of the cell-sized Sention, or perhaps for some energy beings, but i'm having a hard time picturing it for anybody else in a way that's not magical.
It means their biology or some other attribute permits them to produce such structures in such a way that they are more stealthy. For instance, the Laenfa have long leafy bodies. They might choose not to make ships and buildings with solid bulky structures, but build structures that tend to be in more of a framework pattern with each section not much thicker than their bodies, so that someone looking at it from any angle will see mostly just the space behind it, with exception being made only for necessarily bulky parts such as the engine (and not for virtually everything else, for example the large corridors and control areas needed for human ships would be much more compact in a Laenfa ship).
Essentially that's "compact crew quarters" and "compact housing" on the planet. That would plausibly produce a small bonus to stealth, even in the best case scenario of the Sention.
But most things on a ship and many things on a planet would be at best negligibly effected.
Weapons with the same power would essentially be the same size. Shielding that offered X protection would be the same thickness. Scanners with X range would be the same size. Lots of the ship is not going to scale with the inhabitants.
On planets: scanners, shields, would be essentially the same size. The assumed factories, power plants, etc, and whatever buildings are primarily about something other than housing citizens would be essentially the same size minus the space saved for smaller hallways and access points.
In space (the most obvious stuff) orbital weapons, installations, and space docks (since they are servicing/building ships of essentially the same size) would be the same or nearly the same.
I'm trying not to be overly realistic. But it's one thing to gloss over complexities with a simplified mechanic, and it's another to give special advantages with suspiciously thin explaination.