I am looking at the Brenthaven Collins Plus for my Pro3. But, I have an Incipio Feather Advance ultra thin snap on case on it. Does anyone have this combo and know if it will fit comfortably while in the case? I do want to leave it in the case while in the sleeve. I can't find the internal dimensions of this sleeve... Or, anyone know of a sleeve it would fit in while in this case? I of course want it safely padded since I do not have a type cover over the screen. I also want some place to put the pen where there's no chance of it rubbing on the device and scratching it. Thank you!