I'd like to make a pull request to document how to install the mod, but I'm unsure on how to check what dependencies are required. I'm not very familiar with the modding ecosystem.

The latest .jar's mcmod.info shows no dependencies at all, but launching it on top of Meatballcraft v0.16.5-p3 fails during loading since it expects >=modularui-2.4. How can I verify the full dependency list? Are some/any of these dependencies mixin-specific?

Also, just to confirm, the mod works fine as a standalone client-only mod, with some extra features if server also has it installed, right?

Required deps are listed here.

No, this mod is required on both sides.