The Adler-zero conjecture for generic pure generalized NLSM 3-amplitudes

Let $\mathcal{A}^{(3),\sigma}_n$ be a generic, pure generalized nonlinear sigma model $3$-amplitude, and consider any single soft limit obtained by sending one external kinematic deformation to zero. Adler-zero conjecture. For a generic, pure generalized NLSM $3$-amplitude, all single soft limits vanish identically. The calculation for $(k,n)=(3,6)$ supports this behavior, but the source reports no substantial experimental evidence beyond that case, so the conjecture remains open.