Do not top/fim an autoflower. If you do, you will significantly reduce your yield. The inner timeclock of an autoflower plant nullifies any benefit you might receive from pruning techniques.
Do LST/Scrog autoflowers. Moby Dick photoperiod version is a large sativa dominant plant. I would expect that some of the "big plant" genes remain in it's autoflower offerings. Scrog would give you better support than most other LST training methods. The plant could get quite large without the training.