For go fast, perhaps the 3 speed will do, with the 54t chainring, instead of the 50, and either 13, 14 or a 15 t cog,
then you just walk up the hill on the last mile home.

Q: there is the Cycling general category: are you a high rpm spinner,
or a low rpm High ratio masher?

The S bar is not high enough for 5'9'' me, I have an M bar type ..
the AW3 speed shifts quickly.

ratios can be roughly calculated here : http://sheldonbrown.com/gears/internal.html

though I'm unsure whether, since Sheldon passed away ,if anyone has updated the tables for recent product releases

for the BWR , use the SRAM hub data.. the hybrid 7,8,9x3 is a wider ratio internally than the AW3.

BWR could use a single cog too, taking off the shifter and left hand gear shift lever..

I put a Schlumpf mountain drive on my m3, (wide ratios good hill climbing low but probably weighter than you want to add).

after getting the front derailleur mount, a bolt on adapter

custom made for cm wasson, Palo Alto Ca foldabikes dealer.

I'd sell it , [on the verge of returning it] Steve Parry in UK has similar, over there.
then you have a fitting to attach a 'braze-on' front derailleur.

Then you can have a range shift of a 53/39, or 50 /34 double
in place of the single ring, thumb shifter operated .. , not much added weight

a light weight double crank+ the shifter kit, is probably within a pint's weight of the original parts..

with 6 speed there would be 3 shifters , but it sounds like you have only a 1 time downshift , so that wouldn't be too much.,

PM, etc.

[can return it or sell .. at same as return credit would be..
got a FD and a Thumb lever too]


add:
No, the 4 wheel EZ wheel kit, on the rear rack is not bad at all,
I upgraded the front 2.

Those wheels are thinner than Roller blade wheels, still a rubber/plastic 'tire'
and you can just add them to the order list, when you spec the bike.
they roll on the same Industrial sealed bearings as the skate wheels do.