Even if it has more permissions than a normal app, if you have the password and unrestricted local access to the phone you can already put it in debugging mode and connect to it via adb.
Permissions with protectionLevel of "signature|privileged" can't be granted with adb, so having such an app installed would give you more access than you can get via adb.
https://developer.android.com/reference/android/R.attr#prote...