I'd stick with stock to be safe. Your mfg recommends the same width tire for both front and back, and they made your 'ped. This will give you optimal performance according o the mfg.
If you wish to deviate from the mfg's advice you may affect the performance of your 'ped. If you're going to deviate an option is to keep the front stock, and get a slightly wider rear, which grips better and transmits power from the tire to the ground and gets you moving.
What you don't want to do is get a fatter front tire as your steering might become slower. A fatter front tire is heavier and it might make your 'ped feel sluggish. More weight on the rear tire won't affect you as much.