I thought the entire purpose of the RESUPPORTED4 jail break app was it could basically mirror your iphone display on your tv so it wouldn't matter if the Netflix app was updated or not, am I missing something?
Also, that cable is not component but it is a composite cable.
I would bet that cable would work as long as the pins line up it sounds like it can work so if it works for old firmware that means the pins should definitely line up correctly. Now is it a good cable? No, when you pay 7 bucks for a cable you will get 7 bucks worth of cable. It will probably work decently for a while though. If it were all digital cable quality really doesn't matter but when it gets converted to analog it will degrade the quality slightly.