Unfortunately, as of the time I’m posting this comment, the custom character file path for kp 2.1.2 on Android is still “/data/data/com.kemohaus.kemopop/files/custom/characters”. This path requires root access to access on Android devices.
I hope the developers can change the path to “/sdcard/Android/data/com.kemohaus.kemopop/files/custom/characters” to make it easier for players to access.