But if the OP is seeing the UI presented differently by S1-3, on the same computer, then surely it can be set/controlled by the governing program(?) Check out e.g, the Melda Production plugins - they have resizable frames etc too.
EDIT - Ahh - Melda does have the Windows border. ... but original premise still stands - if Cakewalk chose to address it, to make things look sleeker, they could.