The hidden stars are incredibly cool.
However, there is an issue with them.
Due to how the revealing mechanic appears to work, it is very possible that some stars may remain hidden indefinitely as there are no hints or other feedback showing that a star is in the area even if you don't know exactly where.
They do show up as a non-specific sensor contact, but only at a fairly short range. Short enough that with a big enough fleet/sensor level it doesn't appear at all as the star will be revealed before it shows.
What the problem with this then?
Bounties are spawned in systems as per normal, nothing changes here. That includes stars which you have not yet discovered.
And this can lead to situations where a bounty spawns in a system you don't know about, is far enough away from others in it's constellation/area to be non-trivial to find, and you only have the vaguest idea where in a huge area to look for it.
This caused me enough frustration that I disabled the hiding mechanics just to avoid that stuff.
Might be worth looking at some means of telegraphing the presence of hidden stars at a much greater range, especially when the player has a significantly large fleet/sensor range.
Luckily, this mod is worth it for the procgen changes alone. Even despite the weirdness it causes with the system overview UI that doesn't know how to handle >4 moons.