The straight style staircase handrail fits with the Standard Flange and is a good solution.
The images show the difference between the candy cane and the straight.
The junction of the handrail with the vertical post is made with a Standard Alvin Clamp no AIS-44-8, so it can also be used for other purposes.
It can also be used for other types of staircases. Vertical pipes can always be cut to a shorter length. You can also change for another 1.900'' pipe if needed.