Your lower stair steps are too big, and on the edge of too steep, for most building codes. Approx 10 1/4 going and 9 1/4 rise will be both dangerous and uncomfortable to use. The angle is just about ok, but you need to try smaller steps on the straight stretch at least.
Why are none of the dimension round numbers? The outer radius of the spiral parts looks as though you intended 3’6, but it isn’t quite that. And the two floors are quite different.
I’ve drawn most of the lower stairs using a rise of 7", four instead of three spiral steps in the 90° bends, and a going to fit the available length - 10 treads in about 74 1/2" (6’ 2 1/2"), so just under 7 1/2" going.
I used the plugin I mentioned earlier to make two different helical ramp infills, and I ‘hand stitched’ the curved triangular infills. I haven’t done the outsides. You could add that yourself - just draw a series of connected triangles on the endpoints of the curve, make into a component, repeat with a rotation for the other gaps, and smooth the surface.
It was quite fiddly to get the parameters correct for the helical ramp parts. One is 3/16 of a turn, the other a quarter turn. And if you use too few curve segments (as I did initially) the plugin rounds up the number of segments, and ended up too high as a result.
Stairs with spiral ends.skp (53.5 KB)
The stairs look covered externally, but it needs more thought about how you would make curved stringers or otherwise support the steps for the spiral parts of the curve, and actually construct the stairs.
Here is the component ‘in situ’ in your original v8 drawing:
See this related thread to which I responded earlier: