I have had very good luck growing autos under a trellis I use a light mover and I keep the light low at first so not to stretch to much - then I usually only top once around the 5 node - then lst from there on using the trellis to run the branches under. This is about my 5th year growing there was many failed and not so happy grows I have tried 3 different lights so far and 2 grow tents this 2x4 is the best so far the size is perfect for big crops in small areas no wasted space.
Specs:
2x4x70in grow tent purchased for less than $70
Grow light is a 1800w cob LED light stays way cool and grows monsters buds purchased for just over $100
Light mover was $$ but worth it considering how amazing my grows have been
Exhaust fan 200cfm
Carbon filter 4in
Inlet 100cfm fan
2 clip on rotating fans
2 Exhaust O2 bags
6x3 gallon pots best fit or 3x5 gallon pots are best fit
Full line of fox farms nutrients
Total grown at once so far was about 8oz from 6 plants all autos