I have thought of the possibilities. It has an existing derailleur hanger, a 7 speed cassette option, freewheel, IGH, crank arm extenders, 26" wheels and QR axles, plus front suspension fork, all as add-ons for this model. There is a rear stand-on flat bed available too. Our dog has arthritis, occasional flare-ups while out walking make for a long trip when he requires suit casing (75lb) to get him home. Being able to load him on a rear rack would be useful. However, this trike is so purpose built it would be a shame to muck with it. I left the seat belts attached to the saddle just so returning to stock would be simpler.
I really appreciate the assisting features engineered on this trike. The rear steer bar and lift handles are useful when maneuvering the trike in & out of the house and up & down from the porch. It's not too heavy either, and the frame is surprisingly well made.
With 1:1 gearing, small wheels, and short crank arms my cadence is extremely high. I must quiet the torso to smooth things out; not such a bad exercise in form.
Check out this nifty distribution block which links the two rear mechanical disc brakes to one brake lever.