  Schaefer (2024) has recently published observations of binary period
derivatives $\dot P$ for 52 cataclysmic variables, and concluded that these
strongly conflict with all proposed evolutionary pictures for these systems. We
point out once again that using measurements of $\dot P$ is likely in practice
to produce misleading evolutionary constraints in almost every case. The one
identified exception to this is probably the recently-born X-ray binary SN
2022jli, because of its extremely high mass transfer rate.
