Embeddable Lua module system

What? I want to embed some of my own Lua module for plugins. For example, The Vim script has https://github.com/vim-jp/vital.vim that is easy to embed custom module to other plugins.

Why? I want to try and error when I create some of the modules. But currently, the neovim community's approach is hard to apply breaking changes. For example, I think plenary.nvim is being hard to apply breaking change.

Potential existing implementations: https://github.com/vim-jp/vital.vim is the ideal solution, I think.

Potential pitfalls: Probably, it will make the users are being to do Reinventing the wheel but Lua plugin ecosystem will be grown, I think.