Currently it is possible to configure the referenceDepth in rest endpoints so we can limit the number of references (in depth) that are resolved. However, it is not possible to configure the depth of the referenced nodes as the property depth does in the rest endpoint configuration. The existing implementation returns the referenced nodes up to the configured referenceDepth but it is also returning all their children. This is happening because resolve method is always passing a value of -1: https://git.magnolia-cms.com/projects/MODULES/repos/rest/browse/magnolia-rest-content-delivery/src/main/java/info/magnolia/rest/delivery/jcr/v2/JcrDeliveryEndpoint.java#354

In certain cases, users wants a specific depth for the returned "root" nodes but a different depth for the referenced nodes. Therefore, this is to ask for a configuration property that controls the depth of the referenced nodes instead of using the hardcoded value of -1

In some cases when referenced nodes having big tree behind, the reference resolver resolved a very big tree in response which may cause both performance issue and un-responding to front-end side when multiple users calling the same request.