I have a Trailer that folds flat that I can Tow with My Brompton ,

or by taking off the hitch from under the L axle nut tow it with any other Bike.


After Touring and finding the 5 or more bags Off the Bike are a bit of a PITA to deal with

when encountering stairways, the Idea Of a back pack strap Portage bag from the Canoe Voyageurs of the 19th century

has appeal in that you can wear the trailer, and lift the rack-less bike in your hands , to climb and descend stairs
\
Fence stiles , and even cross un ridable places like when the road washes out or the hill side's slide blocks your Route.