Chromium-based:

• SlimJet
• Dissenter-Browser

Firefox-based:

• IceCat
• WaterFox

Some notes:

I removed Cyberfox because it is an outdated browser which hasn't been updated in several years.
The remaining Firefox-based browser commented out to test are unavailable for Linux.

I also tested several browser which didn't work. I left them commented out with FIXME notations in case someone wants to look at them:

• SuperBird: This one had a lot of tracebacks, presumably it uses a different method for storing the passwords than standard Chromium-based browsers.
• Vivaldi & Whale: These are a little weird. They each (if included individually, or the last of both if you uncomment both of them) fail at this line.
  

  LaZagne/Linux/lazagne/softwares/browsers/chrome.py

  Line 95 in f542505

  password = password if python_version == 2 else password.decode()

• Pale Moon: This is a browser based on an old version of Firefox. Perhaps the Firefox code we have only supports newer versions, or maybe they use a different method, but it doesn't work right now.