bread machine loaf size buttons
I doubt it'd increase the proofing time, since that doesn't generally vary with the quantity of dough; the yeast is working in all the dough at the same rate. It would definitely need to increase baking time, though, since it takes longer for heat to transfer all the way into a larger loaf.

Sounds like with that machine you might have to do some non-automatic proofing in order to increase the time, e.g. with a preferment.