Problem:
I believe that a standard way to configure debian packages is through files in the
/etc/default directory (the same way is used in prometheus node_exporter for example: https://github.com/prometheus/node_exporter). This configuration will survive also package upgrade.

Link to question about /etc/default:
https://askubuntu.com/questions/429592/what-is-the-purpose-of-etc-default

Now when I install process-exporter_0.5.0_linux_amd64.deb package, I have to add starting parameters (as -threads=false) directly into a service file (/lib/systemd/system/process-exporter.service), which will be rewritten during package upgrade and is not a recommended practice.

Question:
Is there any reason to make deb package without /etc/default configuration?