> Every time I think about using Scala and go through the list of configurations I need to do, I just give up.
It's pretty easy. You have to setup less things than with Gradle, because SBT deals with all the downloading, installing and managing of the two dozen SDKs Google wants you to use.
> I want a setup that embraces Gradle (even though we love to hate it), Android Studio GUI designers, plugins and annotations.
You can keep all you Gradle configuration. SBT-Android has a Gradle support mode so you can e. g. use the Gradle definitions for your IDE, but enjoy the fast turn-around and compile-times of compilation with SBT.
> Last time I mentioned this, someone pointed me to http://scala-on-android.taig.io/editor/android-studio/ which hasn't been updated in ages.
Yeah. The documentation is at scala-android.org. If you feel something is missing, I think the maintainers are happy to read your ticket.
> Using InteliJ with Android support means always being outdated as it is usually two versions behind from Google's fork.
The current IntelliJ is pretty much up-to-date with current Android Studio.