what do you think is the simplest way to make it so that it is enabled for all domains? i think this should be default behavior. if they should not have aliases, their hosting package should already be set. if they are allowed more aliases, they should activate automatically.
Approval for domain aliases is not based on the fact that an user can or not add them. It's about security issues. The current version is OK. Next version will allow to setup domain accounts for which approval is not needed via the plugin interface directly.