I actually wrote that documentation under their instruction, the browser recommendation is in the process of being updated, that is likely to comprise part of it. I’ve got a couple important things to squeeze into that process this week, hope to make some serious headway tomorrow.
I’ve got to finish a couple things with the fingerprinter, I kind of left it off mid-feature and need to fix it but work has been very busy, but once I fix it I will be continuously doing this and updating the fingerprint screenshot for at least a handful of browsers in default and modified configurations. I have tried it with a hardened non-tor Firefox already using this https://github.com/eyedeekay/firefox.profile.i2p, but now that I’ve actually run a current Tor Browser on a Windows machine and know it has a path I can fetch with an environment variable, that may change to Tor Browser as well pending some discussion. There was some friction shipping an alternate Firefox profile at first. I’ll also be doing probably at least vanilla Firefox, Vanilla Chrome, and either ungoogled-chromium or Brave as well.
On another topic, if we want out-of-router i2p applications, neither disabling the default ones nor writing new ones is terribly difficult. I’ve got a considerable amount of time in it already actually.