Good news! You can now change the Dragon's health and the damage it deals to players. This has been by far the most requested feature for this plugin.

Changelog:

• Bumped config version to v5 due to the addition of Dragon Enhancements and some other tweaks
  • You no longer have to painfully generate a new config - instead you can now use this website that I created:
    https://evs-dev.github.io/edt-config-updater
  • Please make a backup of your old config beforehand!
• Added Dragon Enhancements
  • Set the Dragon's health, as either a fixed value, a random value between two numbers, or a value that increases every time the Dragon is defeated
  • Change multipliers for the Dragon's normal hit damage and the damage the Dragon's breath inflicts on players
  • Suggested by ArimaTheReaper, DraNard, Sookus, & SASKER_R
• Added more XP distribution modes
  • equal: give the same XP amount to all fight participants
  • split: divide the given XP amount between all fight participants
  • killer-bias: give double the XP amount to the Dragon killer
  • killer-only: only give XP to the Dragon killer
  • Suggested by FoxLGV
• Added /respawndragon command
  • Respawn the Dragon manually using the command /respawndragon (permission: enderdragontweaks.respawndragon)
  • Heed the respawn cooldown (i.e. don't respawn if the cooldown is active) using /respawndragon heedCooldown
  • Override the cooldown (i.e. respawn even if the cooldown is active) using /respawndragon overrideCooldown
  • Suggested by Coax32
• Added update checker (can be disabled but it is useful)
  
• Capped max-player-distance-from-end-centre to 46000 to prevent an integer overflow issue
  
• Improved time formatting in messages (#21)

Please let me know in the discussion page or on GitHub if you have any issues or questions regarding the update or the new config updater website.
Also, there are some suggestions of features (like conditions for players to get into the End and support for the Placeholder API) still not included that I may or may not get around to adding in a future update. I enjoy these, so thanks, and I acknowledge them.