Testing in a new version it seems like Cascade Windows does respect the size set with Save Default Window but does not respect the location for the first window.
Command-N (without any windows open) will open a new window at the set size and location and cascade from there on subsequent new windows. Cascade Windows will instead adjust them all to the size set by Save Default Window but always starts the first window at the upper left of the screen rather than the set position.
To my reading, the manual implies that the result of creating four new windows and then cascading them should be identical.
"The Cascade Windows command cascades all open editing windows in the default fashion:
each successive window will be moved incrementally down and to the right (as described
above)."