Anyone? No?! Haha
Sorry only just seen your post. No I would not recommend going stage 2 with out the downpipe.
Revo has spent hundreds of hours creating the map and fine tuning it, so it would worry me if someone wanted to start messing with it. Im not saying he doesnt know what he is doing, but if you are buying Revo then thats what you should get.
Because in theory he is creating his own map, and unless he know the TSI engine inside out then he could create an average or sh!tty map.
Stage 2 revo is a great map, but my only word of warning is make sure your clutch has a lot of life on it or be prepared to get an upgrade in the future as the torque over time will degrade it.