Update >>>>
The L shaped deck engagement pins will, on their own rotate through a small but sufficient range of motion. Such that at some point they angle in the direction of the shroud attachment knobs.
Then ... If you leave your deck on, like I 'did' for HST fan protection, slow mount/remount time for deck and lack of good storage space for deck.
As I motor around doing tractor work, the deck would/could/did swing on its pivot such that the knobs would hit the L shaped deck engagement pins.
Now that Kubota has come out with the HST cover. And because I bought the mower deck stands. I can 'finally' keep deck off for an extended period of time and move it around and store it in a reasonably compact area.