I would assume that seed development would stop as soon as the plant
has been pulled and it would be safe to drop the plant on the ground
without fear of any immature seeds germinating. Correct?

If it is a pernicious weed, the seeds will probably continue to develop. I
would get the plants out of there as soon as possible.

Iris,
Central NY, Zone 5a, Sunset Zone 40
"If we see light at the end of the tunnel, It's the light of the oncoming
train."
Robert Lowell (1917-1977)