Dynaviews are like Images and Text -- they only have an Insertion point so you should be able to select that, but the Other corners are all computed based on the size of the Dynaview
Question - why do you rotate the Dynaviews in The Sheet View and not apply the rotation in the Plan View when you create them?
I define my Dynaview Box Sizes in my Sheet Names so I know exactly how much space I have to work with on my sheet, and then I rotate the Dynaview to best fit my data in Plan View, and then it is automatically rotated into my Sheet with title box as I place the Dynaview on the sheets (manually or automatically - I tend to use Dynaview Collections for everything rather than the Create Dynaview from a Box or Polygon - unless I am doing an Inset on a drawing and then I will draw a Shape (a circle or a polygon for the Dynaview Frame and then use that as needed on my Sheet
Interested to hear why you are rotating after the fact - that seems like hard work to me ...
Alan