I have 2 Sonnet Allegro USB PCIe cards installed in my MP 3.1 and they have 4 external USB ports plus 1 internal( see photo). I'm not really sure what the internal ports should be used for? I thought about using it just as you would an external by running a USB cable through the back but chickened out at the last minute thinking it would cause some kind of problem….or that the cable might melt or something. Any advice on this?