Our Phonegap app using inappbrowser works really well on every device tested except one using Android version 4.3 where the CSS seems unresponsive and the onscreen keyboard doesn't pop up when you tap in text fields. I can't seem to find any documentation on minimum versions of Android for supporting the various Phonegap plugins.
From my experience, I've used phonegap a far as Android 2.1 . The problem you could have on such older versions is the phonegap version.
You should provide further information such as phonegap version.
But I can assure you that Android 4.3 has a very broad support for all Phonegap/Cordova 5+ plugins.
If I were you I wolud try updating phonegap version according to your desire of minimum Android version you want your app to be executed on.
For example, until Android 2.3 on inappbrowser apps it wasn't able to use overflow scroll, so you had to use an external plugin to get that effect, which was really annoying.
Hope this helps.