Precisely. "Let's see how large a boom it makes in the middle of one of our cities!" is a decidedly nonoptimal choice.
She's been peaceful, so far. When confronted by a polite local beat officer, she accompanied him peacefully. When confronted by highly impolite facility guards, she left without violence. They have both direct observational data that she is not currently hostile, and also implied evidence of same from the lack of city-or-planet leveling explosions as she wanders.
The decision maker can believe that she is not a massive danger, in which case immediate overkill violence is essentially pointless.
Or the decision makers can believe, as you state, that her power levels are sufficient to be a danger to nearby people/buildings/cities/planets. In which case the last thing they'll want to do is trigger that danger in the middle of a city full of civilians. (And currently, remember, Taylor is preferentially traveling to those cities.)
These are the people, remember, that after the Book of Darkness affair, ended up hiring the owner and remnants of the book. Being an artifact from the previous war is not an immediate death sentence.