Yes, it’s definitely possible to add multiple chainrings and a front derailleur to the Boda Boda Original! The stock bottom bracket will accept any JIS Square taper modern crank (double or triple chainring); its spindle length is 110.5mm.
The bottom bracket shell will also accept external bearing bottom brackets; its shell dimensions are 68mm wide, English thread (1.37 in x 24 TPI).
Please feel free to contact us if you have questions regarding a specific gearing set up for your Boda Boda Original, we're happy to help!