Something easier to doff than shoulder straps. I am thinking something like hooks that I could shrug and twist out of. Maybe I could rig up a harness with straps that had a hitch system with some sort of rip cord or button popper that would pop the hitch open and drop the cart off the harness clearly.

I'll have to think on this some more.
_________________________
The ultimate result of shielding men from the effects of folly is to fill the world with fools.
-- Herbert Spencer, English Philosopher (1820-1903)