We consider the normalized odd Collatz map T (n) = (3n+1) /2^v₂ (3n+1) as a discrete dynamical system in the ring of 2-adic integers. We show that the carry length m (n) is strictly determined by the depth of the binary prefix match between n and the unique 2-adic anchor =-13. Closed macro-cycles are interpreted as phase-synchronized carry profiles, the existence of which requires strict palindromic symmetry of local 2-adic configurations (kernels). In terms of cylindrical topology, we prove that for a cycle length N > 7, an unresolvable algebraic conflict arises: the loss of injectivity of the right-edge projections is incompatible with the uniqueness of the global Diophantine invariant. This bounds the topological gluing defect (c 4), which, combined with the combinatorial classification of palindromes, structurally precludes the existence of long macro-cycles.
E. Dyachenko (Thu,) studied this question.