Yup! Happy to help answer questions about schema design. So the SpiceDB schema language doesn't inherently have a notion of collections but you can define object definitions as you see fit. For example, you could have:

definition widget {}
definition widget_collection {
  relation member: widget
}

and define permissions on the widget_collection appropriate for a collection. Some of the schema patterns listed in our docs have object definitions that represent collections of objects which will be more concrete examples: https://docs.authzed.com/reference/schema-lang#common-patterns