Dashboard using offline (no Internet connection LAN)

Our team uses dashboard on a LAN without an internet connection. When I tried it with the latest version 2.15.4, the phenomenon that dashboard is not displayed for a long time on the first access has appeared. I have tried this with 2.10.1 and this phenomenon does not appear. When I checked on Chrome's web developer screen, it seems that waiting for timeout occurs when accessing fonts.googleapis.com .
When I examined github repo, find this.
This fix is ​​supposed to access fonts.googleapis.com in index.html.
Is the dashboard a specification that requires an internet connection? Is there a way to use dashboard even offline by setting cache etc.?

Thanks, will look at that.
Maybe this will help https://www.lockedownseo.com/load-google-fonts-asynchronously-for-page-speed/

Hi - any chance you can try latest version in master branch on github ? I now try to load that font asynchronously in the background - so it shouldn't block page loading and should just fail quietly.