A nonempty regular SWAP route

Within the retained regular developed tube, choose a nonzero straight spatial segment of length $\ell$. Choose a departure time after readout, lookup, and the declared processing buffer, with the whole route in the existing time reserve.

For $n\ge 1$, place equal payload registers $A_0,\dots ,A_n$ at equally spaced stations. The payload includes the finite report and every quantum residual to be returned. Prepare $A_1,\dots ,A_n$ in independent blanks $\omega$, and apply successive SWAPs across developed durations $\ell /n$.