OpenWRT worked around this by creating UCI, its own configuration system that it uses to generate all package-specific configuration files: https://openwrt.org/docs/guide-user/base-system/uci

Configuration for all supported packages is stored in files under /etc/config in UCI's own text format, and OpenWRT's init scripts generate service-specific config files based on the UCI settings when the service is (re)started. For example, to configure Samba, users don't edit smb.conf directly, they set UCI settings like samba.workgroup, sambashare.path, etc.

There's a `uci` command-line utility to read and modify settings, and UCI forms the basis for the OpenWRT web interface.

debconf does something similar for Debian packages, though I haven't seen any packages that use debconf to completely supplant vendor configuration formats the way UCI does. https://en.wikipedia.org/wiki/Debian_configuration_system