This exists and is actually the way pharmacy used to work.
Long story short, economies of scale led to today’s system.
In the field of pharmacy, compounding (performed in compounding pharmacies) is preparation of custom medications to fit unique needs of patients that cannot be met with mass-produced formulations. This may be done, for example, to provide medication in a form easier for a given patient to ingest (e.g., liquid vs. tablet), or to avoid a non-active ingredient a patient is allergic to, or to provide an exact dose that isn’t otherwise available.
I did something similar with deluge. Went an extra step and made a script update the deluge listen port.
Wrote down the details here if it helps anyone else. I included the docker config files and some issues I ran into.
https://edmomot.github.io/automatically-update-deluge-listen-port-when-gluetun-vpn-updates/