The new difficulty options menu from Ver. 1.11.36 covers many bases already. Still, certain tweakworthy aspects of the gameplay remain untouched - the Skill Progression (repetitions needed to complete a skill challenge, skill points needed in a category of the skill tree before you can pick skills from the next higher category) is one of them.

DOE Skill Progression (for starters in just 2 difficulty levels) makes specializing and complete mastery either much easier (by about 50% with the "easy" setting) or forces the player to go broader in the skill tree so that it takes much more time (and levels) to finally master a skill and it connected higher category skill brethren (by about 400% with the "very hard" setting). The effect on gameplay style is profound as  "very hard" will require much more patience while at the same time ensures that there are always interesting goals to work for on the far horizon. "Easy" on the other hand allows players to much more quickly get into a possibly heroic role they want to play in the game (like Veteran Sharpshooter or Ace Pilot).

Based on the receiption of DOE Skill Progression I will do additional difficulty levels later on (quite tedious work to do this). Please also note that about 1/3 of the skills dont allow to change their repetition settings via sf1edit currently, so you will occasionally find unchanged skills/challenges.

Easy   50% repetitions, 2 points required to advance a skill tree category | - 1 % suggested XP Modifier
[Vanilla     100% repetitions, 4 points required to advance a skill tree category]
Very Hard 400% repetitions, 7 points required to advance a skill tree category] | +2 % suggested XP Modifier

XP Modifiers can now be realized via XP Unchained


How it was done
Unilke most other DOE mods DOE Skill Progression is an .esm mod, made with xEdit. No scripting involved. 

Installation

• With Starfield's June 2024 update (Creations) installation has become much easier (the Plugins Enabler mod and therewith SFSE is no longer needed to install this mod)
• Just download the mod version of your choice (Easy or Very Hard) from the files section, unzip it and place the .esm file into your game's data folder 
• Double check ingame in the Creations menu (available from Main Menu), then Load Order submenu, whether your chosen .esm has a checkmark. Ideally move it down the load order, so that it is loaded last (this prevents it from being overwriten by preceding mods)  
  

Credits
Without xEdit and Elminster's work of a genius all this would not be possible, so, many kudos to Elminster and team.

The whole DOE Series and friends
DOE Resources
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DOE Sell Price
DOE Sell Price at Starfield Nexus - Mods and Community (nexusmods.com)
DOE Starpower
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DOE Loot
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DOE Ammo Rarity
DOE Ammo Rarity at Starfield Nexus - Mods and Community (nexusmods.com)
DOE Ammo Prices
DOE Ammo Prices at Starfield Nexus - Mods and Community (nexusmods.com)
DOE Skill Progression
DOE Skill Progression at Starfield Nexus - Mods and Community (nexusmods.com)
DOE Research
DOE Research at Starfield Nexus - Mods and Community (nexusmods.com)
DOE Less Shortcuts
DOE Less Shortcuts at Starfield Nexus - Mods and Community (nexusmods.com)
Replicant
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XP Unchained
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Sneak Damage Hotfix
Sneak Damage Hotfix at Starfield Nexus - Mods and Community (nexusmods.com)
Equipment Level Requirements (ELR)
Equipment Level Requirements (ELR) at Starfield Nexus - Mods and Community (nexusmods.com)
NGXP Plus / NGXP Plus Risk
NGXP Plus at Starfield Nexus - Mods and Community (nexusmods.com)
Minimum Enemy Level
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Fauna Protection Initiative
Fauna Protection Initiative at Starfield Nexus - Mods and Community (nexusmods.com)
Spongecop
Spongecop at Starfield Nexus - Mods and Community (nexusmods.com)
Building Rarity
Building Rarity at Starfield Nexus - Mods and Community (nexusmods.com)
Minimum System Level
Minimum System Level at Starfield Nexus - Mods and Community (nexusmods.com)