Generally, Inventor lets you edit a features parameters during forward creation and also in a post-placement edit state.
However, in Drawing manager this is not the case with the Detail View. During forward creation you can select the circular boundary/fence or a rectangular one. After placing the detail view you cannot edit the boundary - this is an inconsistency in UI and should be adjusted to perform like the other parts of Inventor.
It's really inconvenient to create a detail view, then have to delete and recreate because you want to change the fence/boundary style. JDI !!
Thanks