In a Personal Log Book, the holder can log anything they wish; some things are not acceptable to the Authority and they clearly list those to avoid confusion. For a checkout to be meaningful, surely there should be a record of it, what better place than the log book?
How can loggable dual training take place without an instructor rating on board?
Simply because its not for the purpose of qualifying for a licence or rating! (Art 80) Don't confuse what is creditable with what may be recorded. Anything can be recorded and Art 79 states "any test" not one required by regulation.