Worked on a photo print pipeline around that era and the shipping side is always the part nobody plans for. Color profiles, trim bleed, and then a whole customer service load when a card lands late for someone's birthday.
Ink and Switch's stuff always makes me want to go rebuild something, and the homepage being playable is very on brand for them. Curious how much of it is bespoke versus falling out of their own Automerge tooling.
If you'd like to rebuild a letter, we recently published the editable version of the system (which is also a Patchwork):
https://tenfold.inkandswitch.com/
Worked on the ad insertion side for a league feed once, and hydration breaks exist because they're the only reliably schedulable stop in a 45 minute half.
Part of the value of F-Droid is the curated distribution model that hopefully catches the worst behaving developers that think they have a god given right to your data though.