If more than one device is shown, you will have to use "adb -s emulator-5554 install <APK>" to direct adb to the right location. Otherwise, I do not understand either the preferred choice of adb.
I tried SwiftKeyboard. Crashed. But at least it got installed and configured on our box.
The Directx-backed version we now shipped offers better performance. But now it cannot be compatible with APPs written to use GLESv1. We will look into the issues to determine the cause of the crash.