After a long wait, fully down to me, 1.21.1 support is now here in 1.7.3 alongside many new cool features by FireML which can be seen as follows ...

Note: the plugin now requires Java 17 to run. At the time of writing this, 98% of servers run Java 17 or above already.

• Added /emf gui, this is a GUI to let players interact easier with the plugin.
  
• Added MiniMessage support.
• Added option to swap round comma and full stop, e.g. £1,040.65 and £1.040,65
• Added option to add fish straight to inventory, the option can now be found in the config.yml file.
• Added the option to use biome sets, which can also be found in the config.yml
• Added new baits menu to go alongside the new GUI.
• Added click actions & commands when players interact with the GUI.

• Added better customization of the bossbar.
  
• Fixed various bugs.
• Improved various behind-the-scenes systems.