Hey..
Unless your running a bigger turbo then upgrading to a larger injector is pointless.. We were running the KO4 on the Golf flat out, 98.9% duty cycle on the wastegate, and there was still plenty of headroom in the standard injectors.. Ed30 injectors are the same as S3 as I'm sure your aware..
Once you go larger on the turbo then you will need a larger injector than the S3 item, I'm using the RS4 injectors on mine, as are lots of others without problems.. They have been ran up to 510WHP on a GTI in the US so they can support high power levels for sure..
I'm not sure about the TT-RS injectors, they could well be a good option, but it depends if the spray patturn and fitment into the head is the same as the S3 / RS4 injectors weather they will be a viable option..
Hope that helps you out a bit!