Even though some roots are coming out the bottom doesn't mean that the cup is filled with roots.
Wait until they're about this size.
Or you can just grow it to maturity in the cup.
People transplant and train autos all the time without issue. Done correctly, there should be no slow down because of transplanting.
Even Mephisto, who only sells autos, recommends starting in solo cups and transplanting.
I wouldn't know..........I've never grown that strain.
I have no idea how much my plants drink........I grow in coco and keep them saturated at all times. 1/2 gallon twice a day for every plant.