Keybase developer here. Keybase does automatically update on Mac, and you can check if you're out of date on the CLI with `keybase update check`. Additionally, the "widget" popup from the system tray will display an out of date banner automatically.
4.2.1 was a bugfix release that only affected Linux and BSD, so we didn't push out Mac or Windows releases for it.
Keybase uses root privileges only for making the magic /keybase directory available, where you can access your KBFS files (the redirector allows different users on the same system to see their own files). Keybase and KBFS run as unprivileged daemons (via the systemd user manager where available).
As giancarlostoro mentioned, you can unpack the .deb file and run the binaries out of there. If you put the binaries in your $PATH, you can even symlink the systemd unit files to your ~/.config/systemd/user and use the systemd user manager to manage your custom Keybase install. Note that the KBFS mount will not be accessible at /keybase, but instead at another location writable by your user (see https://keybase.io/docs/linux-user-guide#configuring-kbfs).
I have friends that I know use keybase for work with a specific corporate account. I want to talk to them using their private account which I can't because the app only supports a single logged in user. So, is it easy or possible to have multiple accounts logged in and used at the same time? This includes that support for android also.
Maybe the chat application should be extracted into a separate more native application maybe since another "problem" I see my friends talking about is that it is too slow.
Actually there was a discussion about adding Keybase to F-Droid repositories. However, it seem that contributors in that issue failed to build this app.
Would be great if there are helps or guides from Keybase.
4.2.1 was a bugfix release that only affected Linux and BSD, so we didn't push out Mac or Windows releases for it.