[!IMPORTANT]
Paper 1.20.4 build 445 and above has built in support for enabling gravity block duplication. Here are the docs: https://docs.papermc.io/paper/misc/paper-bug-fixes#duplication-bugs (allow-unsafe-end-portal-teleportation)

If you are using this version or above, do NOT use GravityControl. Use the option built in to Paper instead. Ensure you uninstall GravityControl before enabling the Paper option. If you don't, gravity blocks will be duplicated twice.

GravityControl

Liberate your server from the anti-dupe bourgeoisie.

Paper plugin to enable gravity/sand duplication

Downloads | Discord

Features:

• Enable duping for each different block
• Allow duping in some worlds but not others
• WorldGuard integration
• Enable sand duping on Paper servers
• 1.18-1.19+ compatibility. Use version 1.3.0 for 1.16-1.17 support.

Commands

Configuration

Default configuration below. Everything is explained with comments. If you have issues or need help, reply here.

# Worlds where gravity duplication is enabled.
# `*` means all worlds.
# WARNING: World key is used, NOT world name.
# For example: `minecraft:overworld` rather than `world`.
worlds:
  - "*"

# Blocks for which duping is allowed.
blocks:
  - "sand"
  - "red_sand"
  - "gravel"
  - "anvil"
  - "dragon_egg"
  - "white_concrete_powder"
  - "orange_concrete_powder"
  - "magenta_concrete_powder"
  - "light_blue_concrete_powder"
  - "yellow_concrete_powder"
  - "lime_concrete_powder"
  - "pink_concrete_powder"
  - "gray_concrete_powder"
  - "light_gray_concrete_powder"
  - "cyan_concrete_powder"
  - "purple_concrete_powder"
  - "blue_concrete_powder"
  - "brown_concrete_powder"
  - "green_concrete_powder"
  - "red_concrete_powder"
  - "black_concrete_powder"

# List of WorldGuard regions where duping is allowed
# `*` means all regions. Checked based on end portal coordinates.
regions:
  - "*"

# If GravityControl should check for updates on startup
update-checker: true

Support / Discord / Contact

Join Discord for support/help or feature request. You may also make issue here on GitHub or reply on PaperMC Forums to my post.