Revit needs to reformulate its stairs and the ability to design them.
You have to think of it as a model object, where you can edit face by face, edge by edge, element by element, with more definition.
Currently the stairs behave with a semi-automatic entity, but they do not return very detailed computations nor do they allow basic designs to be solved, such as the central beam in the landings.

This time I want to propose that you use the same code that the side beams have, to create the central beam. So that it can be made "open" or "closed" and generated at rest. That a profile can be assigned to the central beam and it would be nice if it had some parameter to assign a support for the steps in each tread.

Archicad solves it very easily and with better detail.

They should copy the good ideas or skills from other programs to make Revit much better.
Thanks