Edit of coolwsd.xml causes conflicts on upgrade

I installed coolwsd using aptitude, and made some changes to /etc/coolwsd/coolwsd.xml by running coolconfig set. Several times in the last month, the shipped version has changed which causes my automatic update script to fail and I have to resolve manually.

Configuration file '/etc/coolwsd/coolwsd.xml'
 ==> Modified (by you or by a script) since installation.
 ==> Package distributor has shipped an updated version.
   What would you like to do about it ?  Your options are:
    Y or I  : install the package maintainer's version
    N or O  : keep your currently-installed version
      D     : show the differences between the versions
      Z     : start a shell to examine the situation
 The default action is to keep your current version.
*** coolwsd.xml (Y/I/N/O/D/Z) [default=N] ? dpkg: error processing package coolwsd (--configure):

I would like to avoid these errors please, which means a way to set configuration without changing a shipped file.

For almost all software I use these days it is standard to have a local file where we can make edits to settings without causing a conflict every update? E.g.

/etc/ssh/sshd_config.d/
/etc/sudoers.d/
/etc/apt/apt.conf.d/