I think once you go away from stock hardware it's like a domino effect! More air generally means more fuel (i.e. Intake = HPFP) then to get the flow of air out of the turbo you'll need a larger bore DP. I think this is why people see modding as addictive. It's more of a knock on effect than an addiction.
The early Cupras and ED30s were generally making 300-310. Looks like the FL cars are making a little more power at Stage 1. I'd be interested to know what this is attributed to and how safe it is running that power and in turn that heat with no mods. Not sure if the gains are all the way up the range. My car made 305bhp at GIAC Stage 1.