Yes, Hyvä supports other modules, but only if they are compatible or have a compatibility module.

It is designed to offer the flexibility and extensibility needed to customize solutions for any project size or complexity. Its modular architecture allows users to add additional modules as required. The core modules come with pre-defined functions, such as navigation and authorization, and core business logic that can be easily adapted to different scenarios. 

Furthermore, the solution can also integrate user-created modules and third-party plugins. This gives users numerous options for customizing their solutions depending on their specific requirements.

In order to work with Hyvä, modules based on the Magento Luma or Blank themes require a Compatibility Module. This is because Hyvä uses TailwindCSS and Alpine.js, whereas Magento uses LESS, RequireJS, jQuery, Knockout.js, and other libraries. Compatibility modules essentially replace incompatible Luma code with code that works with Hyvä. Shared compatibility modules are published as in the hyva-themes composer namespace. License holders can upvote modules they’d like to see implemented by Hyvä on the Compatibility Module Tracker. Some compatibility modules may not support all features of the original module.