Contributing to modules successfully - recommended approach?

Forgive my ignorance - I’m looking for guidance on how to best fork and/or contribute to existing hugo modules.

Specifically, there’s a gallery module I’d like to make some adjustments to, and potentially extend functionality:

  • convert to webp option
  • resize the original images to a max size, rather than showing the original unprocessed image
  • alter to use bootstrap instead of lightbox2

ie, the changes go beyond modifying a shortcode file. I could, of course, duplicate the shortcode file and place in layouts/shortcodes/ in my site repo for the 1st two adjustments.

I’ve tried forking on github and started on the journey of updating paths within the module to point to my repo instead of the source etc.

In my testing I’ve renamed mgallery → tgallery almost everywhere, and pointed to my repo.

Is this a suitable approach? It feels as though this isn’t an appropriate way to do this - given those changes wouldn’t want to be propagated back…