I just went through the yearly process of renewing a digital certificate and, for the first time, I did not need to run Java software inside a Windows VM. Huge win.
After following the official process, installing an Ubuntu package, and adding a browser extension, the certificate still was not available for export in the software. Their support team said Linux was not supported and that they would reschedule the procedure so I could run it on Windows.
While waiting, I asked my agent to see if it could find the certificate on my system. It gave up three times and needed a few hints, but after about 20 minutes and some reverse engineering of the extension, it found the certificate buried in a folder in my home directory. With a few OpenSSL commands, my accountant was able to use it for the tax filing.
I still have not received the reschedule link from the company.