Here's an update fixing bugs of the last beta version and preparing the grounds for 1.21.1 support:

• Bug fixes:
  • Fixed tridents being upside-down when untrimmed
  • Fixed the texture of spears trimmed with Charge in the inventory
  • There is no longer a recipe toast every time you trim a tool
• Added compability for 1.21.9-1.21.10:
  • Support for 1.21.5-1.21.8 might no longer be added but support for 1.21.1 is now planned
• Now you can dismiss the missing assets warning if it is not relevant, e.g. for servers.

Also, it wasn't mentioned in the last changelog but Tool Trims is now compatible with resource packs that change the tool textures. As long as the textures follow more or less the shape of the vanilla ones, the trims will look quite good on them. Here's an example with the resource pack Fresh Weapons & Tools: