We discuss 𝒩=1 Klein and Klein-conformal superspaces in D=(2,2) space-time dimensions, realizing them in terms of their functor of points over the split composition algebra ℂs. We exploit the observation that certain split forms of orthogonal groups can be realized in terms of matrix groups over split composition algebras. This leads to a natural interpretation of the sections of the spinor bundle in the critical split dimensions D=4,6 and 10 as ℂ2s, ℍ2s and 𝕆2s, respectively. Within this approach, we also analyze the non-trivial spinor orbit stratification that is relevant in our construction since it affects the Klein-conformal superspace structure.