Problem/Motivation
The intent for Starshot is to allow Drupal to compete in a very competitive CMS space. Some competing solutions, such as WordPress, offer plugins that provide very robust solutions. For example, to manage events, popular WP plugins provide a substantial set of features (including things like registration) and then offer a paid version, which offers additional features (such as paid registration, reminder notifications, and more). Drupal could, in theory, provide all of this in a recipe, but the challenge is that not every site will need every feature.
Proposed resolution
Allow recipes to include "subrecipes". For a developer experience (and to reduce noise for searching projects on drupal.org and in the Project Browser) these would be better if included in the same git repo.
It would be even better if the recipe creator could indicate which subrecipes are "suggested" (would be enabled to be applied by default) vs. "available" (site builders could enable them if need, and optionally install them later through Project Browser).