You know there's really a wider range of good tyres in the larger size, right? Not wider, I grant you. There's no issue with the fold, but I guess it could lower the BB height a little, though I have read that with the fatter tyres on, there's no appreciable difference in diameter. If that's really the case, I might go for 349s on my Mini Moulton, where skinnier tyres would suit the intended purpose.