I'm not at all sure that you can create a new option to
systemctl and I've never attempted it in all my time working on kernel internals.
However, there are a vast number of things you can do with
systemctl on a typical Linux distribution to make managing your applications easier. I guess that you know that there are a great number of options other that the 4 you list: status, start, stop & restart on a typical
systemctl implementation.
You can edit the actions of options to address what you want to happen to your applications management.
I'm not even sure that what I've written here is any help to you at all!!! Perhaps you could elaborate on detail.
Refs:
How To Use Systemctl to Manage Systemd Services and Units | DigitalOcean
Understanding Systemd Units and Unit Files | DigitalOcean