There has been discussion of the real virtues of potting on across the forum over the years. I'm interested in the evidenced practice too. I don't really get the science behind the idea of having to pot on.
As with many of these questions, I think it would be very easy to set up some tests over the summer to see what happens, setting up various planting conditions in as similar settings (earth, water, seeds etc) as possible.
It would be interesting to bring curiosity and investigation to the question....