Nah, I think I am good

.mozilla/native-messaging-hosts/ff2mpv.json

@@ -1,7 +0,0 @@
-{
-    "name": "ff2mpv",
-    "description": "ff2mpv's external manifest",
-    "path": "~/bin/ff2mpv",
-    "type": "stdio",
-    "allowed_extensions": ["ff2mpv@yossarian.net"]
-}

install.sh

@@ -57,8 +57,6 @@ echo 'Switching shell to zsh...'
 chsh -s $(which zsh)
 
 mkdir ~/bin/
-wget https://raw.githubusercontent.com/woodruffw/ff2mpv/master/ff2mpv -O ~/bin/ff2mpv
-chmod +x ~/bin/ff2mpv
 
 vim +PlugInstall +qall
 echo 'Done'