Do you mean remove all jaas bundle from startup.properties and put them into a feature?
If so, -1. Given the very basic role jaas bundle plays here, a lot of other karaf functionality depend on it, such as admin, shell, management, features, etc. I believe we need the jaas for JMX/SSH/Webconsole aslo. startup.properties is the place to put some very basic bundles, which can do self-boot for container, if we remove jaas bundles from startup.properties, we also need remove almost all other karaf bundles from the startup.properties, which I think not doable, think about without features related bundles ready at very early stage, who take responsibility to launch the features from features.xml?
In summary, the jaas related bundles isn't be optional, it's very fundamental thus must be available at very early stage.