It could really use an overhaul. Maybe a faction directly, key word search ect. Faction directory is really what I want but that would probably be more work for modders.
Alex said he wants to redesign it at some point, but only after most of the features and content of the final game are in place, since these might require additional codex functions.
I speak from my infinite ignorance on "how SS and it's mods works" but wouldn't it be a "simple" matter of checking the subfolder's name and use it to discern: this is from ss+, this from diable, this from blackrock and so on?
for the most part, yes. but that's still not exactly a very convenient way if you don't know already know where to start looking. there are also a few ships with a hull-ID that isn't exactly the same as their in-game name. for example, BRDY's "0-Series Nevermore" has the ID "brdy_nevermore_00", and "brdy_revenant" and "brdy_scarab" had their ingame names changed to "Knight" and "Weevil", respectively.
if you do need to find a ship's ID or mod, afaik the easiest way is opening the ship_data.csv files and using notepad's search function, as those files do contain the exact in-game name. same for weapons. that's what i do when i need to find an ID for adding something with the Console Commands mod.