Smart invert colours finally works as it should on this beta. Safari works like it should and finally shows the dark keyboard when Smart invert is enabled. It also finally work for the news app and other apps seems to works properly as well.
The only problem remaining now is the home page menu and notifications will invert if you are in dark mode and if you zoom, it will invert as well so you need to turn off dark mode and turn on smart invert to work without any issues but just making a quick siri shortcut will solve this problem for now.
Its finally a good update for me and I hope the final build will at least stay like this.