Out of frustration with how GitHub handles tabs, a Safari extension has arisen.
The point of tabs is that each user can view them according to their own preferences, and this extension lets you do just that—set once how wide you like your tabs, and have it apply to everything you view on GitHub.
Feel free to hide the settings toolbar button after configuring it to your liking.
Now also works on GitHub subdomains like gist.github.com
Up to six family members will be able to use this app with Family Sharing enabled.