this plugin is a recreation of the original clumps plugin, all credit goes to InventoXtar
https://modrinth.com/user/InventoXtar Here's a page to his profile with all his plugins on it.
https://modrinth.com/plugin/clumps-plugin the original clumps plugin for 1.21.8 and below

(Original features are the same as the updated version)

Features

XP Orb Merging: Automatically merges nearby XP orbs within a configurable radius to minimize the number of entities.
Instant Absorption: XP orbs are absorbed directly into the player's XP bar upon proximity, eliminating the delay typically associated with collecting orbs.
Customizable Settings: Configure the merging radius, minimum XP required for merging, merging interval, and instant collection radius through a user-friendly configuration file.
XP Boost: Players near merging XP orbs now receive an XP boost, increasing their total XP gain.
Merge Animations: Enable particle effects when XP orbs merge for a more visually appealing experience.
World-Specific Settings: Customize XP orb behaviors for different worlds (e.g., Overworld, Nether, etc.) with individual settings for radius, merging frequency, and other parameters.
Prevent Orb Duplication: Prevents the duplication of XP orbs in high-density areas to reduce server lag.