I personally start all my seeds in solo cups because I like to make sure they germinate before I start preping pots. However it is true that autos are a bit more sensitive to transplanting then photoperiods. It’s best to go from which ever method you choose for germinating directly into your growing medium.
Photos actually respond well to up-potting, so I tent to go from solo, to like half gallon then to their final pots.
I like 3 gallons for my autos, and 5 gallons for my photos. I was once told that when growing in soil, you want about one gallon of soul for each month the plant is alive.
Hope this helps 🌱