I’ve recently started to use Safari more and more. I am liking the changes to navigation on mobile, the mobile/desktop sync, and tab groups. These days it’s having less challenges with compatibility too…
In recent months apple have started supporting the chrome extension api - as such I wonder if it is reasonable to hope for a Zenhub extension (both for public github and enterprise deployments…) 
Hi @planetf1 and welcome to the ZenHub Community!
Thanks for this great feedback re the Safari extension; it has been submitted to the Product team. In the future, please feel free to submit feedback and ideas to our ZenHub Product Board.
Thanks again and see you around in the Community!
I have submitted the idea multiple times to the product board, any idea if it will be available?
@humbertogontijo While this may not be the answer you expected, I did go ahead and recompiled the Chrome extension into Safari extension by following safari_web_extensions documentation from Developer documentation and " How to get Google Chrome Extensions in Safari" video on YouTube.
and I can confirm that it works in Safari this way.
We don’t have any plans on our short-term roadmap to introduce an extension for Safari.
The reason being for this is due to the Safari review process for extensions. At Zenhub, we ship new features and fixes at least twice a week. However, the Safari review process is too long, and therefore this is not compatible with how we ship our features.
However, we are exploring ways to allow the webapp to provide more functionality that GitHub does, so Safari users can have a more complete experience in the webapp (you can access this through app.zenhub.com).