fourrings wrote:
....
...All steps will be of same height, even with additional thickness.

How can first not change if change tread thickness w/o changing flooring?

dpb -- your reasoning of not having a solid edge for stair-nose to sit
on is exactly my concern. I do believe that with enough weight on the
edge, it will crack. So there are two possibilities: [1] take the
rounded edge (1/4") off existing tread flush with stringers OR [2]
trim tread flush with stringers and riser (~ 1.5"). With method 1, my
concern is with extending total overhang. And concern with either
method is will trimming flush with stringer eventually loosen
underlaying treads?

I don't follow the stringers here -- risers, yes, stringers, no.

You already have my recommendation/preferred mechanism which you didn't
like is to replace treads as stairwell originally designed. You need
the overhang (that is, not cut off even w/ riser) and the overhang has
to be solid enough to serve the purpose.

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