I switched from Franz to Ferdi to Ferdium and then I noticed all it's doing is creating PWAs in profiles, which made me use Chromium with some cookie deletion and privacy add-ons and just install the applications I needed as PWAs. You can start Chromium with a separate profile and auto open all of the apps which you can't install as PWAs in tabs, and you can move the tab bar to the left side. Then you basically have Ferdium with extra steps and better efficiency.
I buy them from the company which makes the lock. If I need an extra key, I make it myself with the machine at my makerspace. People who give their keys away to keymakers and give them their addresses obviously have bad opsec.
You just have to (encourage others to) register on an instance with less than, say, 1000 active users. I think that's already taking care of most of the issue.
I switched from Franz to Ferdi to Ferdium and then I noticed all it's doing is creating PWAs in profiles, which made me use Chromium with some cookie deletion and privacy add-ons and just install the applications I needed as PWAs. You can start Chromium with a separate profile and auto open all of the apps which you can't install as PWAs in tabs, and you can move the tab bar to the left side. Then you basically have Ferdium with extra steps and better efficiency.