i'm not sure how one'd use self-leveling stuff on a vertical surface ( riser ) but we only do resurfacing/repairs for a living,,, good prep is the key & the work's always mechanical - no ' silver bullets ' NOR ANYTHING from an apron store,,, you'll need polymer-modified mtls such as used in dec conc overlays.
you make neat edges from forming correctly & utilizing your well-developed SKILLS but no one ever did it right the 1st time,,, you may want to hire this work & watch while learning,,, retired masons often make the best teachers !