See the mod list here

Settings

opinionated:

• set menuBackgroundBlurriness to 0
• disabled, pauseOnLostFocus (alt-tab without esc menu opening)
• disabled allowServerListing (you appear as "Anonymous Player" when hovering over a server's player count you're on)

popular:

• Disabled V-Sync
• Set FPS to unlimited
• Cleared Sodium donation button
• Set brightness to full
• Set GUI scale to 3 (Large)
• enabled toggleSprint
• disabled narratorHotkey
• set the textBackgroundOpacity 0% (à la fastchat)
• skipped the tutorial (move, break tree ect..)
• skipped skipMultiplayer Warning
• skipped hideBundleTutorial
• unbound the save & load creative toolbar keys
• set music volume to 0%
• enabled darkMojangStudiosBackground (logo color when launching)

Disabled mods

Feel free to re-enable them in your instance's mod list

• Xaero's Minimap
• OrthoCamera (orthographic view)
• Chat Heads
• appleskin
• Concurrent Chunk Management Engine (Fabric) (not compatible with Flashback)