You can stay on Nova 7, it's not going to stop working. Nova 8 is what you want to avoid, so you just can't let it update to a new version that will have all of the bullshit put in.
Obviously that's not a permanent solution but there's no reason to throw away Nova 7 right now if it's works for you.
The last clean version was Nova 7.0.57
Install that APK, redownload the Nova prime app from Play store, they work together fine.