Question

Me and my friend are having an argument. He claims that you should transplant your weed plant multiple times and that results in better yields.. is that true ? I claim that that has no effect because I start my seeds in their final homes

I always plant in final homes. Transplanting you run the risk of damaging roots and transplant shock which may stunt them. Why take an unnecessary risk if you dont have too?

Goodness no, transplanting is not a stress issue, done correctly. In my experience, plants love growing into their home and then getting new soil to grow into.
Roots are tough, you can manipulate them at will. I would always break up the bottom of the old planters root mass before transplant. Never a problem. Roots want new area to grow into. You can't go wrong giving them that.

Up pot every chance you get imo. Transplanting is easy, a good way to recharge your soil, and fun to watch the growth spurts.

Just do your transplants in the dark.

I transplant at least 3 - 4 times depending on the final size:



They love it! (In fact, they love it so much, you can see the accidental clone I got on the left after transplanting.)

If you don't transplant, you cannot water properly and you will be guessing how much water to use. Transplant, soak, drain, dry, repeat.