I've been to a couple of Edo era castles in Japan lately and I have found the surviving stairs to be high, narrow and irregular; is this a deliberate choice to add to the passive defense of the castle or due to laxer stonemasonry at the time?
Is there information on European stone castle stairs/steps?
You may be interested in this response from /u/mormengila few years ago discussing the direction of spiral staircases' curvature and its effect on sword fighting. There isn't any discussion of step irregularity but a later comment on the historiography of medieval defensive architecture indicates that there isn't much besides observing castles for historians to work with.