Growth question?

My auto yeti is doing absolutely amazing! My auto northern lights and auto nerve gas are shorties! I've attached a couple pics of each...being autos, should I let them go or can I trim them down some how. I'd hate for the amount of growth underneath everything to go to waste. The last 2 pictures are the yeti just for s's and g's

My personal experience with autos is they generally don't like trimming since they have less time to recover. But to answer your question: your plants look healthy enough to sustain removing the lower branches.

I hope it helps