Currently, if you have the screen unlocked you can press space bar to instantly move back to yourself, and hold space to keep it locked on yourself.
I suggest that if you have the screen defaulting to locked on that holding space allows you to move it around like when it is unlocked. Releasing space pops the screen back to you.
I think the best you can get is changing the lock/unlock hotkey to spacebar. Hit it once to unlock and hit it again to lock.
If you click the eye at the bottom of the UI next to the minimap it stays locked on. There's a shortcut key to toggle this as well, but I forget what it is.
The shortcut key is Y.
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