the presence of dbus support inside jackd has always been controversial. Jack1 does not (did not?) do this because I disagreed with integrating it directly into the jackd server. Jack2 does have dbus integration built in, but it uses the same manual page on most systems as jack1.

it isn't intended that the user would ever need to be aware of or configure dbus interactions. the use case you're interested in is what we would call an edge case, and there's increasingly less tolerance for spending resources catering to these when there are so many non-edge features and functionality that are required by so many more people.