Which /etc zsh related files are safe from OS update overwrites?

We have added custom modifications to the /etc/zshrc, which work. The issue is following an OS update (for example recently went from 13.2 to 13.3), the file gets overwritten and we lose our modifications. Does anyone know whether there is any other zsh related file in /etc that is safe from update related overwrites? We are eyeing /etc/zprofile as a possibility, but not sure if that is any less at risk? Does Apple provide any guidance here for system administrators?