ESC key to leave any mouse dragging process we decide to abort like: changing values, taking files from project panel to comp panel etc
Sometimes we start changing values, like those of position and scale but we found out in the middle of the process that we want to abort and the only way to revert that is by finishing the process and, only then, use CTRL + Z to revert which is less productive than just hitting ESC before releasing the mouse button.
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