I just checked in X2, and having the main Screenset locked or unlocked did not affect the behaviour I am referring to in the OP...

I'm now not sure what issue you meant in the OP then. You said you switch between Track View and Console View by hitting D, but hitting D alone can't switch between the views AFAIK. What I can reproduce in SPlat whether the Screenset is locked or not is this:
 
1. Open new project
2. Drag MIDI file into TV 
3. Maximize MultiDock (CV or PRV)
4. Hit D to collapse it
5. Double-click the MIDI clip to open PRV (expand MultiDock) again
 
I expected the PRV to appear in the maximized MultiDock, but it only half opened.

icontakt
You said you switch between Track View and Console View by hitting D

Hitting D toggles between showing and hiding the MultiDock.
 
I have Console View in the MultiDock, so I am able to switch between Track View and Console View by hitting D.

Oops, sorry, I read it wrong. I thought it was PRV.

Yeah, I never have to use shift + D, just hitting D alone toggles between the 2 view states

I actually use Shift+D a lot since I often want to see both TV and PRV at the same time (to do clip editing and notes editing at the same time). I'm glad a Shift+D issue (in which hitting D and Shift+D a few times used to initialize the height of the MultiDock) was fixed in.....Braintree IIRC.