Hi! I use Blackrock as part of the Starsector+ modpack (which combines several mods together). And I don't know if this issue has been brought up before, but Blackrock's economy seems a bit overpowered than anyone else's by a large margin. For example, you can usually buy supplies for half of what you can get them in Corvus (normally the cheapest/largest supply producer in vanilla Starsector), and the same for fuel in comparison to Askonia (again, normally the cheapest/largest supplier in vanilla). It also overproduces other goods and sells them cheaper than every other sector, though not to the same extreme as 50% off the next cheapest planet like with fuel and supply. It's a massive boon for anyone looking to profit from trade... to the point of feeling like an exploit.
I suspect the issue is the combination of it's 10^8 population and extremely high stability, probably due to Blackrock fleets being deadly enough to wipe out any pirate that dares even look at a trade route. Have you considered nerfing the Anar economy, or is it unparalleled might intended due to the faction's backstory?