Plank and log brace, revamped stairs
So now that we have a system of log and plank pillars that can also be rotated horizontal, why not update the stair models to take that into account, as in don't put in any horizontal support.
Make the stair a 1x1x1 block with edges that taper slightly so that the stair would be neatly propped up by a horizontal plank or log pillar right below, and or at the opposite edge at the top of the stairs. (see attached file)
The model no longer has a top landing. It can be the floor in the next block, or the support pillar itself can become the step (either top or bottom). If no support as in a horizontal pillar or a wall is in place at the top of the stairs, the stair falls.
A log or plank brace would be a useful model addition that can serve to keep stairs propped up along tall walls. It can be used in many other situations where the half-timber slope wall inverted is not visually appropriate.