Is There A Reality Patrol?

Does the Time Patrol guard the history of only a single planet? I thought so but maybe not. We are told that Earth will always be the human planet and that the Danellians are the evolutionary successors of humanity but, on the other hand, time travel will be discovered in a galactic era, the Danellians are not necessarily confined to Earth and the chaos that the Patrol guards against is a cosmic phenomenon.

I am fairly certain that the temporal vehicles used on Earth have access only to the history of Earth - they can hardly have or need a cosmic range - but the Patrol must be active wherever humanity is, which is on a galactic scale in some eras. The role of extraterrestrials is not mentioned. Do the Danellians cooperate with the evolutionary descendants of other races?

SM Stirling's "A Slip in Time" is the first story in which we see a timecycle make an interplanetary crossing but that is only between a human colony on Venus in the twenty fourth century and Earth of the twentieth century. Although surprising, it falls well short of a cosmic range.