  In this note, we shall point out that all ``numerically calculations'' and
figures in \cite{CaFrLeVa-23} are wrong because these calculations are based on
some incorrect formulas. Furthermore, by pointing out several serious errors in
\cite{CaFrLeVa-23} and especially by Section 7, Proposition 7.1, Remarks
7.2--7.3, and Section 8 (a result of A. Pierzchalski and B. {\O}rsted) we show
that the conclusions published by Matteo Capoferri, Leonid Friedlander, Michael
Levitin and Dmitri Vassiliev (J Geom Anal (2023)33:242) as well as the main
``algorithm'' theory of the book \cite{SaVa-97} are completely wrong. Finally,
we explain the correctness of proof of Theorem 1.1 in our paper \cite{Liu-21}
by giving some remarks and putting the whole proof in Appendix (see also
\cite{Liu-22b} and \cite{Liu-22c}).
