Optimize Routing Zone Resource Usage (4.2.1)
In Apstra version 4.2.0 and later, resources used for routing zones are already optimized (enabled) by default. This means VRF configuration is rendered only on leafs where at least one server-endpoint is a member of a virtual network in that routing zone.
In Apstra versions earlier than 4.2.0, all routing zones required resources. When you upgrade an Apstra server from a pre-4.2.0 version to version 4.2.1 or later, optimization is disabled by default. Since enabling optimization is disruptive, you must manually enable it yourself in this case. (Remember, currently you can't upgrade to major releases, such as 4.2.0.)