Restrict usernames hook

First, Many Thanks for the release as an official wp plugin.

For a long time im using Restrict usernames plugin and similar snippets. They work fine with the default wordpress login, but this baby seems to bypass some hook in the check username call.

Is there a way to make shure the ajax call includes the same rutines or loads later in the check usernames hook, so other function can return a false callback/ verification.

Or anyone can help me out a direction here. I really need to restrict usernames for all my installs for clients and organisations.

Thanks

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