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Hi Daniel,
For construction/detail drawings, I would recommend using 3D rebar modeling if you need accurate reinforcement plans, sections, quantities, and schedules. You don't necessarily need to model the entire stair as an in-place component just for reinforcement; the approach depends on how the stair was created and how much control you need over the geometry.
For a typical reinforced-concrete stair, you can model the reinforcement directly with Rebar in Revit and then create plan/section views for the construction drawings. If the stair reinforcement is mainly being documented rather than coordinated/fabricated, 2D Detail Items and Detail Lines can also be a practical option.
Regarding fabric sheets, Revit supports fabric reinforcement, but whether it is the best choice depends on the actual reinforcement design and the type of stair. For conventional stair bars, standard Rebar is usually more appropriate.
I would suggest starting with the stair geometry, then placing the main longitudinal bars and distribution bars in 3D, and using dedicated plan and section views to produce the reinforcement drawings. This gives you a much better workflow if you later need schedules or quantities.
Hope this helps.