350hp in a FWD hatchback? Er, no thanks. The 275hp stage one tune is already too much, IMO.
Steady on...400 BHP would be a walk in the park.
The throttle isn't a switch...it can be modulated...and if the map is tuned to be soft when coming on boost, traction isn't as much of an issue as people make out.
I've driven several 360+ BHP FWD cars with a far lesser chassis than the Golf Mk5/6 that manage just fine.
EDIT,
Oops...should have read further down...