Interesting. My, perhaps wrong, visualization of the janking effect, without the display update, concerns resizing, or showing, a column or pane in a web app. During the resize, the content in both frames are not updated until the resize is complete under certain (most?) conditions.

"If an undue delay is likely to be caused, the work already completed is processed and the update phase yields to other update phases for unlocked content."

My interpretation for a pane/column resize or hidden to visible operation: display-locking reduces jank if I could operate on these elements with the display lock tools. This jank reduction produces more fluid updates in elements not affected by the lock.

Question: If sub elements have complicated draw/render cycles, how will the interplay of locks at different layers affect the result? Composing objects with libraries that use these locks makes me wonder about this issue (or if I make sub-components myself).