Is there a vimari or vimium port for safari on mojave?
vimari currently has a somewhat experimental process to compile and install it locally for Safari 12, detailed here:

https://github.com/guyht/vimari/blob/master/docs/safari_12.md


  Note: We are currently working on improving this installation flow, as well as the extension itself. Because vimari now has to be released
  as a Safari  App Extension instead of a Safari Extension it
  requires some fundamental changes to the code. We can't guarantee that
  all the features work in  this version. It's a learning process for us
  so bare with us.
  
  
  Clone this repo
  
  $ git clone git@github.com:guyht/vimari.git

  Open the Swift project located at app_extension/vimari in Xcode
  Configure the Signing settings for both the vimari and extension targets    to use your information rather than the Vimari
  team's (see this SO
  answer
  for more information).
  If you want different settings than the default ones, make your changes in    settings.js. You can always come back later to change
  the settings again.
  Build and run the project (⌘ + r)
  An empty GUI box will show up - ignore it (we'll fix it later). Go to    Safari and open up settings (⌘ + ,). Go to Extensions and
  you should    see vimari in the list of extensions. Enable it.
  You may now press stop in Xcode and close Xcode. The extension will be    available even if you restart Safari.
  
  
  This was tested on High Sierra with Safari Technology Preview (version
  12). Let  us know if something is not working for you.