Front ports have low power and are often improperly shielded, they rarely conform to USB spec, I don't recommend plugging anything delicate into a front port that you value. I've seen them destroy USB sticks, make wifi flakey, and even crash systems.
If the case is an OEM such as Dell or HP, or a high end aftermarket case, it's probably going to be okay, but if it's a cheap aftermarket case, don't plug anything of value into them.