NullCascade did a phenomenal job on the original Proportional Progression. This new version builds directly upon his previous work (although the original mod is not required to use this version).

Review of Original Mod
Here is the description NullCascade gave of the original mod:

Features:
Without configuring, this mod doesn't do much. However, it provides a detailed config file that lets you change skill level multipliers based on the following criteria:

• Global scale. All progress will be modified by a given value.
• Skill-based scale. A given skill will level faster/slower.
• Level-based scale. Alters the leveling rate based on the player's overall level.
• Skill level-based scale. Alters the rate based on the skill's level.
  

Requirements:

• MWSE 2.1. Note: You should update MWSE before installing this mod. Version 1.3.0 of this mod requires the Feb 3 2024 build of MWSE.
• herbert lib (v1.3.0+)
  

New Features

1) Backwards compatibility

If the original mod was installed, the config file is imported the first time this version is launched. Afterwards, the original config file will be ignored. There's also a button to import the old config at any point, should you wish to do so.

2) MCM Support

All settings are configurable within the MCM and take effect immediately.

3) Multiple profiles

There's a "Profiles" page of the MCM that lets you add/change the current "profile". Each "profile" is basically its own config file, so this provides an easy way to swap between different configurations of the mod.

Also, each profile is stored as its own json file, which means it's very easy for other mods to add their own profiles, and to transfer profiles between computers. Profiles are stored in the "Data Files/MWSE/config/PPE/profiles/" directory, where the name of a file corresponds to the name of the profile (as it will be shown in the MCM).

4) New slider options

You can change the modifier of a skill based on whether that skill is a major/minor/misc skill. There's also a modifier for skills within a classes specialization.

5) More Granularity

There's a new option: "Gradually change level modifiers", which lets the modifiers for different levels/skill levels gradually change from one slider value to the next. E.g., if you're supposed to get 100% xp between levels 10-19 and 200% between levels 20-29, enabling this setting will mean you get 100% xp at level 10, 110% at level 11, 120% at level 12, ..., 190% at level 19, and 200% at level 20. If this setting is disabled, you would get 100% at levels 10, 11, 12, .., 19, and then 200% at level 20.

There are also options to customize how many sliders appear. Newly added sliders will be set to sensible default values, based on existing config values. These options are explained in more detail in the MCM.

Upgrading from the original mod.

If the original Proportional Progression mod is installed, it will be deleted whenever the game is launched. So you don't have to worry about uninstalling it.

Note: the original Proportional Progression marks its config as a "mod" file, meaning that your config will be deleted if you try to uninstall it using a mod manager. If you want its config to be imported, you should keep the mod installed.

Feedback

Feel free to share how you think this mod (or its mod page) may be improved, or how things could be done differently. I'm open to suggestions.

If you think of a feature that might be nice to add, let me know. I just might add it.

If you find a bug, I'd encourage you to report it here, preferably in the "Bugs" tab.