Long-time visitor, finally made an account here on the forum in order to properly comment on mods such as this one.
Definitely a must-have mod for me! With the ships fitting seamlessly into the vanilla game's visuals and the faction itself being based in canonical lore (if altered slightly in order to allow them to still exist), it really helps it all feel like it well and truly belongs in the Sector. What issues I do have with it are rather trivial compared to what it does right, though I'll still voice them here for the sake of feedback.
-In the 8.2.8 update, the new elite Mayasurian sub-faction shows up in the intel tab as a separate faction, which it presumably shouldn't be.
-Some mod, I'm not yet sure which one (checking through them all now, and will let you know when I find it), adds an orbital station to Mairaath. This in itself isn't an issue, but the fact that it belongs to the Persean League is. Visiting the station still leads to Mayasura's market, but the station itself belonging to the League will likely cause problems in the (admittedly unlikely) event that the League and Mayasura come to blows. I'm not sure what solution would be prudent to take, or if it even is something you can deal with on your end as it's another mod causing it, but I figured you'd like to know that there's a mod out there which may cause trouble with this one in that sense.
-The adjectives. I combed through the thread to see if it was talked on before. Thankfully I saw your explanation about Mayasurian referring to the people of Mayasura, and Mayasuran referring to the navy itself. While I can't currently think of a real-life group that has different adjectives in this way, that's not the main problem I have with this. The problem I've found is that there are some points where this rule isn't being followed, such as the intel tab referring to them as "the Mayasurans" when by the aforementioned rules the people as a whole would be known as the Mayasurians. The mod description at the beginning of the thread also contradicts the rule, referring to the entire group as the Mayasurans, while also calling it the Mayasurian fleet. Thankfully, I imagine this would be fairly simple to fix— I've even gone into the files and done so myself when playing with previous versions of the mod. Personally I think it may just be easier to pick one over the other to refer to all of it, but that's your call of course.
-The faction's description in the intel tab is incredibly long; much longer than any other faction in the base game as well as any modded one I've personally seen. It also refers to the Mayasurian fleet, which plays into the point made above. Looking back, I noticed it's actually the description used for the mission "The Last Hurrah", which I imagine is why. This is also something I've fixed for myself when using previous versions, and would be more than willing to help put together a faction description that matches the vanilla ones in terms of length and concision.
That's about all that I can think of. The only other things I can think of are lore-related, which I'm not sure if that's relevant enough to really nitpick— though I'd certainly love to get into the nitty-gritty of the story, haha. Like I said before, what this mod does right far outweighs any issues I've found with it, and what issues I have found with it I'd be more than happy to offer whatever help I can with.