Just because someone has had different results doesn't make them a fool. I can vouch for his experience level. Personally I don't transplant but I also would t expect a dramatic decrease in yield.
the fool part was to impress the grativy of the wrongness
for the last 5 years this has been my work ......making auto flowers produce better then photos with thc counts to be equal or better (terepene count is impossible to match)
he called it a myth.......it is not it is good advice
when u let the plant grow into a 3 gallon container it hits the walls and then starts to tendril out ......taken that plant and moving it to a 7 gallon planter during the 45 days of flowering the roots do not make the tap roots they just tendril out ........leaving a good deal of the lowest soil and the highest amount of water untapped .......really try it one time and be ready to waste 2 planter .....when it is done u gut and dry harvest look at what u made look at the stalk then slice the planter in half and look at how the roots formed
i done growth experiments with and without rooting hormones .......i messed with planters too (soil bags vs old style planter)
when i started this i heard ppl talking shit about auto plants .....got alot of bad advice from ppl doing the photo tricks it took me 2 years (every 2 weeks 3 new plant) of experiments to learn who is telling the truth about autos ......hell i spent 700 bucks to get a my dx tester to get thc results on soil and feed plans
transplanting is a mistake with autos ......it does not work like it does with photos ......autos have a set time table u can extend it with feed on point but the genetics of the plant are much faster then any photo ........autos are 100% feed based plants photos are light and feed based