A nonempty regular SWAP route

Choose a straight developed spatial segment of length $\ell >0$ in the retained regular convex tube. Choose its departure time $t_{\mathrm{d}}$ after readout, lookup, and a positive processing buffer, with the entire route in the time reserve.

At stations

place equal finite payload registers $A_j$. Initialize $A_1,\dots ,A_n$ in independent blanks $\omega$. At hop $j$, apply SWAP to $A_{j-1},A_j$ across developed duration $\ell /n$.

The payload may contain the classical report, represented on its diagonal algebra, and any returned finite quantum residual. It is not the continuum coefficient itself.