This is not guitar related, but IS related to using Firefox to view Tomo's content. If you are using Linuux as your desktop OS, i've noticed that firefox stutters when playing these vimeo videos, and have found a solution. I am using Ubuntu and also Debian Linux, and if you add the package to the OS, it solves the issue.
In a terminal type:
$ sudo apt install org.freedesktop.Platform.ffmpeg-full
This added package fixes.