The plugin has a solid foundation, but I think there are weak points to improve. Just to clarify, I tested the plugin with Minecraft version 1.21.8 (the most recent stable version).
I would recommend that instead of keeping separate addons like DynamicMenu or EMenusSounds, it would be more efficient to integrate them as modules within the main plugin project. You could add an option to enable or disable them via config.yml. That would help avoid possible conflicts.
The plugin claims compatibility up to 1.21, but in reality there are quite a few errors that I’ll attach in a separate post, so as not to damage your reputation here in the review. Also, to respect what you mention in your description. Still, it would be ideal to adapt the code to ensure stability in current versions.
I think it’s a priority to fix the issue where players can extract items directly from the menus. It happened to me with the initial menu (test). I managed to take several ender pearls, diamond blocks, and gold blocks.