  We present a map between the excitation of the symmetric-product orbifold CFT
of $T^4$, and of the worldsheet-integrability description of $AdS_3\times
S^3\times T^4$ of Lloyd, Ohlsson Sax, Sfondrini, and Stefa\'nski at $k=1$. We
discuss the map in the absence of RR fluxes, when the theory is free, and at
small RR flux, $h\ll 1$, where the symmetric-orbifold CFT is deformed by a
marginal operator from the twist-two sector. We discuss the recent results of
Gaberdiel, Gopakumar, and Nairz, who computed from the perturbed
symmetric-product orbifold the central extension to the symmetry algebra of the
theory and its coproduct. We show that it coincides with the $h\ll 1$ expansion
of the lightcone symmetry algebra known from worldsheet integrability, and that
hence the S matrix found by Gaberdiel, Gopakumar, and Nairz maps to the one
bootstrapped by the worldsheet integrability approach.
