KnownControllers was deprecated in 1.5. But if you search the spec for KnownControllers you will find that it recommends to use KnownControllers in a few places.
Maybe we should remove these, and at these places suggest a solution that does not need KnownControllers
<instruction replace KnownControllers with KnownDevices in 18.104.22.168 Exchange of Certificates>
<instruction remove KnownControllers in B1.2 xsi:type>