So I found a bug fix that has existed since iOS 8.2.
If you're in private browsing mode (yes, I am prepared to cop crap about it) and you close all the windows, then press 'Private' button to go back to normal browsing, it used to show the last closed tab in the switching animation; that's been fixed finally.
A bug I have found is that in some stock apps (especially Podcasts) when double pressing the home button, it animates to the Home Screen and then cuts to App Switcher. I know this is a beta, and a first beta of a major update, just like to make sure everyone is informed!