Automatic load of extensions is implemented for all Content Manager extension points: Core, Content Manager Explorer (UI), and Connectors

Content Delivery extension points indeed do not have such capability and all extensions are loaded during service startup (requires a restart when Add-on is added or updated)

Due to technical limitations as well as the fact that customizations are used more on the Content Manager side, we are not considering adding automatic load for extensions to Content Delivery services

In case you do experience issues with Content Manager extension points please raise a regular support ticket