Could attackers cancel a spiral stair's defensive advantage?

Were there tactics that could cancel the defender's advantage on castle spiral stairs?

Not easily. Builders used step height, stair width, and spiral rate to keep attackers from deploying polearms effectively.

Builders shaped the height and width of the steps and the rate of the spiral to constrain movement. The geometry made it especially difficult for troops climbing upward to deploy long polearms. A castle stair was an engineered fighting position as well as a route between floors.