Here’s the most recent thread I know of that addresses this, but there are others:
https://forum.inaturalist.org/t/is-there-any-possible-utility-for-observations-of-cultivated-crops-or-harvested-products-photographed-in-a-market-at-home/39195
I agree that these observation can be very useful for many reasons. In general, if humans didn’t intentionally move individual organisms like these, the observations shouldn’t be marked as “not wild”.
In terms of collecting them for viewing, I would guess an observation field is the best way. You can definitely make a new observation field that meets your interest. I would do some searching to see if there are any that already overlap (I searched quickly for “hitchhiker” :https://www.inaturalist.org/observation_fields?utf8=✓&q=hitchhiker&commit=Search) and didn’t see much in use.