Currently, it is possible to add custom criteria for feature gating. You can create user targeting rules based on user attributes such as email and user ID, and additional ID types can be added in project settings. These can be used for all new experiments, allowing control over the experience a test user sees.
However, there isn't a feature to set these custom criteria as default options for a project. The ability to add these as default criteria options with a dropdown menu is not mentioned in the current documentation.
That being said, we are working on Templating features, and any default configuration criteria, including custom field defaults, are being considered. This includes the possibility of having default custom config for metrics so when the feature gate is created, the custom default metrics are selected/not selected.
In terms of the level at which these metrics are custom to, we are considering project-level defaults. This would be particularly useful for organizations with multiple teams utilizing different repositories, allowing for defaults to be set based on the specific project.
Please note that these features are currently in the scoping phase, and we are actively seeking input on feature requirements.