  The purpose of the present Comment is to point out the connection between an
approach to spawning and regularization that was recently introduced by D.
Mendive-Tapia and H.-D. Meyer [J. Chem. Phys. 153, 234114 (2020)] in the
context of the Multiconfiguration Time-Dependent Hartree (MCTDH) method, and
earlier work where adaptive variational quantum propagation based on the
Local-in-Time Error (LITE) was introduced [R. Martinazzo and I. Burghardt,
Phys. Rev. Lett. 124, 150601 (2020); arXiv:1907.00841 [quant-ph] (2019)].
Furthermore, we show that the LITE represents a gauge-invariant distance which
provides a natural, physically sound tool for adaptive quantum dynamics.
