Quaternionic encoding Q²=−3 of the Syracuse map, 3-state Markov chain (rank-1 kernel, exact gap 1), affine group Γₚ ≤ AGL (1, p), gateway set Gₚ°, Legendre channel, ergodic drift D=log (3/4) <0, CLT, Cramér large deviations, SU (2) density, and model contraction criterion.
Ricardo Hernández Reveles (Sun,) studied this question.