As the current modded 1s are so far just a simple "yank up the boost" efforts, givin only 20KW more, but increasing the lag even more, many customers really can't wait to get 6in1, and way over 200bhp. Add a supercharger and get 300+bhp, like we've on so many e46s.
I4 petrol models have a 51/49 weight distribution, which actually manages to beat sportscars like 350Z, RX8, '05 Mustang and SLK! Since 1 has a front-mid-engine layout, a sixbanger shouldn't sacrifice much of its balance.
Compare this to fwds like Opel Astra Turbo which has a full 64% of its mass on the nose!