There should be some way to edit objects within the site context. A couple things that I can think of specifically would be an option to make the generated topography flat as I'll tend to ignore most very slight grading and make my toposurface in Revit all at the same elevation, but when the Enscape site context is brought in, the topography changes about a foot across the <300' span of site I have modeled in Revit. Another thing would be an option to adjust the height of the generated buildings, I noticed when I loaded the project location into Enscape that most of the surrounding buildings are much shorter than my building when the buildings actually surrounding my site are 4 stories tall. The other thing I noticed was that there is a 4 lane road in front of my building but the automatically generated road is dramatically divided.
The demo video showed the site context with basic trees, cars, stop signs, etc but I've come to the realization that those must have been place manually within Enscape, would be cool if stuff like that could populate automatically too with the ability to move and/or delete them within Enscape afterward. Excited use this awesome new feature regardless!