It would be great if you could mark the Android app as “movable to SD card”.
By setting android:installLocation to auto in the manifest.xml, the user is given the option. By default, the app is still installed on internalStorage.
All data on the SD card is encrypted by Android.
All data on internal storage is encrypted as well (at least on everything less than say 7 or 8 years old). What would be the gain here, also given the app is just a couple of MB in size?