Currently systemd units for packages developed under the Whonix umbrella are located in lib/systemd/system (or etc/systemd/system). And installed by make install with the usual DESTDIR support. This works for Debian and perhaps Fedora based distributions, but is not 100% convention conform.
As per daemon(7), section Installing Systemd Service Files, Quote:
"At the build installation time (e.g. make install during package build), packages are recommended to install their systemd unit files in the directory returned by pkg-config systemd --variable=systemdsystemunitdir (for system services) or pkg-config systemd --variable=systemduserunitdir (for user services)."
Therefore, for better platform / porting support, we should