Diplomacy : Reduced Trade Settlement Penalty
The last settlement captured or obtained by an AI faction receives a massive trade "penalty" making it impossible to get it via trade if the faction is too passive to expand. For some reason, this penalty is included in the "Relative faction strength" malus in the trade tooltip.
Even if it’s a low level minor settlement in a bad location, they won’t accept to trade it for a high level much better settlement which is ridiculous.
To keep things balanced, this mod only reduces the "recently acquired penalty".