I think it should, file system APIs of OS usally treat them as normal drives, NT based Windows systems (xp newer) also let you mount drives to forder in computer management, but i think UE4 should work fine even without it. Ofcorse i assuming you have SD card reader and not using something wierd. i think 64GB should be ok but it might run out of space very quickly if you plan to put projects in it too. You can also consider just buying external hardrive 
And besides… why you come asking this here? just try it 