Hello, I have some ideas which might be cool to have.
First one about selling blueprints at Prism Free Port, how about option option to make independent faction able to teach blueprints which players sell them? Like pirates do when you sell them at black market? Its funny what only player and pirates know how to use blueprints, but rest of factions is not, and I'd like to have more options to affect the sector. Also I think its might be expanded to other faction as well, so they can teach sold blueprints, but limit it by their doctrine, like if faction is Midline, it will teach only Midline blueprints and so on.
Second about alliances, I think cool ideas, raise relation with faction for all factions of alliance which player joined, lets say you want some faction to join your alliance. And another idea, is simple alliance relation, like when faction joins alliance, they have shared relationship with all other factions, and work like one faction in this regard.
And about relations, some mods force max relationship between two faction, I think cool idea to make game more random is option to ignore max relationships. Also about options, I think good one is marine multiplier for invasions, and option not to send futile invasions, where faction sends invasion force less than needed for capture.