Comment on “Spontaneous baryosynthesis with large initial phase”

Recently https://arxiv.org/pdf/2512.11011 set out to improve on previous work from 1994 by Dolgov and Freese, who used a small-angle approximation to derive the yield of spontaneous baryogenesis from a rolling phase, a pseudo-Nambu-Goldstone boson coupled to the baryon current. The goal of the recent paper was to investigate what happens when the small-angle approximation is not imposed. I point out a serious technical shortcoming in their derivation.