A free mod for Mount & Blade II: Bannerlord, by Vaeringjar.

V’s Logistic XP Skill Levelling is a skill levelling mod for the game Blade II: Shadow Legends.

This mod is based on the idea that every level should be made accessible by a certain amount of experience, regardless of the player’s performance. The more difficult the level is, the more experience you should have to pass it. This way, it’s not only possible to have a better progression through the game, but it’s also possible to make high-skill levels accessible in less than a M&B development cycle.

The smoothing out the skill level increases and decreases can be seen in the graphs (images).